Post on 14-Aug-2015
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Mr. Geoffrey Allen Wardle MSc, MSc, C.Eng.
MY NEW CONDENSED AIRCRAFT STRUCTURES
DESIGN DEVELOPMENT CAREER OVERVIEW.
This is an overview covering 16 and 1/2 years at BAE SYSTEMS MA&I (Military
Air & Information) in design development work, my Cranfield University MSc
Aircraft Engineering, my University of Portsmouth Advanced Manufacturing
Technology MSc, and British Aerospace (Military Aircraft Ltd) structural test
work, as well as my current capability maintenance work, research work, and
future career aspirations see also my current work LinkedIn presentations.
Senior Design Development Engineer.
Authorized release under the terms of the UK Official Secrets Act and ITAR restrictions.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
This presentation covers major contributions I have made to BAE SYSTEMS (Air Systems Division) formally British Aerospace (BAe), from 1990-2011. This covers work at BAe Brough STF site 1990-93, and BAE SYSTEMS Warton / Samlesbury, unit from 1999-2011, and MSc joint project work.
Included is some of my post BAE SYSTEMS design studies in support of a paper I am writing for the AIAA from 2012 to date.
I was granted a National Interest Waiver Employment Visa for the United States of America on 11th February 2013 for an R&D design post at a US aerospace prime but the post was cancelled on 23rd May 2013 due to budget issues within the company and the US the visa expired before other opportunities came to fruition.
Abbreviations and Terms used in this presentation are clarified below:-
STF = Structural Test Facility: ATDF = Advanced Technology Demonstration Facility:
SPF/DB =Super Plastically Formed and Diffusion Bonded (structures formed from Titanium sheets in one process eliminating the need for mechanical fasteners and assembly):
RTM = Resin Transfer Molding non-autoclave method for composite part manufacture:
RAF = Royal Air Force: RN = Royal Navy: CFC = Carbon Fiber Composite: CDA=Concept Demonstration Aircraft: HT = Horizontal Tail: VT = Vertical Tail: SWAT = STOVL Weight Attack Team: UAS = Unmanned Air System: FA-2 = Fighter Attack-2: CTOL = Conventional Take Off and Landing F-35A variant: STOVL = Short Take Off Vertical Landing F-35B variant: CV = Carrier Variant F-35C.
INTRODUCTION.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAe BROUGH STF DEVELOPMENT OF MILITARY AIRWORTHINESS QUALIFICATION TESTS.
SP
F/D
B I
NB
OA
RD
FL
AP
ER
ON
MO
ME
NT
MO
ME
NT
MO
ME
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SH
EA
R
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FIXED L/E
STRUCTURE
SPF/ DB Ti Foreplane structure,
SPF/ DB Ti Engine bay doors
structure,
Figure 1(a) Eurofighter Typhoon
wing showing CFC structure and
SPF/ DB Ti Flaperons,
Figure 1(b) G.A. of Eurofighter
Typhoon SPF/ DB Ti structures,
I developed the structural
qualification test program for
Eurofighter Typhoon SPF/DB Ti major
structural components at RAE
Farnborough and conducted this
program at BAe Brough in 1990-1991,
reporting to the Eurofighter Joint
Structures Committee, and Military
Airworthiness Authority.
This enabled the production of these
components for all subsequent
Typhoon aircraft , and for the process
to be maturely applied to the F-35
engine bay doors.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAe BROUGH STF DEVELOPMENT OF MILITARY AIRWORTHINESS QUALIFICATION TESTS.
The Eurofighter Typhoon CFC composite wing which
are also fuel tanks consist of two wing skins and an
internal structure as shown in the previous slide, the
major load bearing structures are the wing spars and
skins. The lower wing skin is co-bonded to the spars
eliminating mechanical fasteners in the highest
loaded wing skin reducing not only the overall weight
but the thickness of the wing skin.
From 1991-1993 my major role was to developed the
structural qualification test program for Eurofighter
Typhoon lower wing skin co-bonded “J” addressing
design configuration issues, for the Eurofighter Joint
Structures Committee and Military Airworthiness
Authority, enabling the first flight target be met and
full scale IPA aircraft production to start.
Eurofighter Typhoon Co-bonded Wing Configuration
structural configuration issues
reduction of bondline peel stress
test „t‟ pull configuration
max stress at flange toe n/mm2
Figure 2(a) G.A. Typhoon CFC Spar structures,
Figure 2(b) Typhoon CFC Spar issues,
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
My major role running in conjunction with new
airframe structural development and
qualification was the running, fatigue
inspection, and fatigue damage repair
development for the full-scale airframe
structural tests of Harrier GR-5, and Harrier T
Mk4/ Mk2 (which supported the structurally
identical Harrier FA-2 fleet). These MAFT‟s
which were run ahead in fatigue cycles of the
operational aircraft enabled the end users i.e.
RAF and RN Fleet Air Arm to be apprised of
through life structural damage issues and
methods of repair before an aircraft became
unsafe or failed in service. These repair
schemes when approved were certified through
the Military Airworthiness Authority.
One of my major contributions in this field was
the teardown inspection of the Harrier TMk2 /
Mk4 , where major potentially service life
ending damage was discovered in the centre
fuselage. I developed an inspection and repair
methodology for this damage which enabled the
Royal Navies Fleet Air arm FA-2 aircraft to
remain in service for ten years longer than
would have been the case.
BAe BROUGH STF MAJOR AIRCRAFT FATIGUE TESTS.
Figure 3(a) RN Harrier FA-2,
Figure 3(b) Harrier Centre Fuselage Structure,
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Warton ATDC Low Observable Technology Integration IPT.
My first major design role within BAe / BAE
SYSTEMS upon re-joining the company as a
design engineer post University of
Portsmouth MSc in January 1999, was develop
low observable structural concepts for the
wing leading edges and weapons bay doors
for the Anglo French, Future Offensive Air
System project.
Further work on FOAS involved the CFC
structural layout design of the wings of the
non-flying pole signature measurement
airframe shown in figure 4.
Another major work was to investigate new
airframe manufacturing methodologies
required for BAE SYSTEMS to build low
observable aircraft in production quantities.
My final work on FOAS in as part of concept
engineering before moving to JSF, involved
concept design trade studies for engine
intakes for the evolving FOAS aircraft studies.
Figure 4 The BAE SYSTEMS full-scale FOAS low
observable non flying technology demonstrator ,
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Warton ATDC FOAS Concept Engineering.
One of my first major design UAS concept design role was to conduct trade studies
for leading edge and intake LO configurations for both the manned and unmanned
elements of the FOAS project from 1999 to 2001 (project cancelled in 2005).
The released concept designs are shown below as figures 5(a) and 5(b).
Figure 5 (a) The BAE SYSTEMS MA&I FOAS
Manned element,
Figure 5 (b) The BAE SYSTEMS MA&I FOAS
Unmanned element,
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Samlesbury F-35A HT Test Block Structural Design Team.
Figure 6 The BAE SYSTEMS HT Test box design and
structures team Mr G. Wardle Concept Lead fourth in
from left completed HT test box in background.
My first major design role on the JSF/F-35 project
2001, was to design major components of a
structurally representative test article for the CTOL
AV-1 Horizontal Tail (HT) to investigate the
mechanical behaviour of the actual SDD phase HT
when subjected to real flight loads.
Because there was no mature design at this phase of
the program the major components and the
manufacturing methods for this test box would form
the basis for the final production HT, and generically
would form the template for the STOVL production
HT. This would enable both CTOL and STOVL major
control to be produced from cousin parts on the
same production line reducing costs significantly I
took design from concept to detail part design for
manufacture.
This design program was completed to cost and on
time, although there were issues in manufacture with
the new processes, fibre placement of the HT skins
was not continued into the final production program.
The structural layout of the test box is shown in for
the F-35A shown in figure 7.
The build to responsibility for the production build
articles for HT was given to BAE SYSTEMS Brough
site.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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Figure 7:- F-35A Horizontal Tail into which the BAE Systems HT test box design contributed.
F-35A HT on painted A/C LM Fort Worth TX.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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BAE SYSTEMS Samlesbury F-35C CV Outboard Wing Design Team.
Figure 8:- The wing fold design incorporated a new multi lug rotary actuator driven
wing fold joint of which neither LMA or BAE Systems had any experience.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Tier 5 IPT Lead Mark Dugdale / Mike Grant
Build Line Support TBD
Sub-Systems
Integration Russ Brigham
FTI
Integration Joe Cookson
Electrical System
High Cooling Power
Coax
Business
Management TBD
Manuf.
Integration Paul Needham
Assembly Planning
WSTGE
Assembly Tooling
Mechanical Installation
Electrical Installation
Engineering Integration Support
Neil Caruthers
Composite
Skins and
Panels
Wing Fold
Interface &
Fold Rib
L/E, T/E & Tip
Interfaces &
Structure
Internal Sub-
structure
Spars & Ribs
Wing Fold
Building
Block
Wing Structural
Integration Mike Grant
Jo Dewhurst
Jas Sandhu
Geoff Wardle (LD)
Stuart Reid
Paul Metcalfe
Phil Hancock
Ravi Sharma
Mark Dugdale (LD)
C Bridgwood
Paul Metcalfe
Jas Sandhu
FE
Modelling
Alan Church
Bus Mgmt
Structures
Simon Harris
C Bridgwood
Mike Welch
Sub-Systems
Manuf Integ‟n
Design
FTI Integ‟n
KEY
Integration
activities
PAO Mass
Properties Dave Bennett
Empennage
Shared
Resource
Lead Designer:- Designing the CV Outboard wing test box and running the team.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
I was responsible as the F-35C Outboard wing Building Block as IPT Design Leader for
creating a test article to meet the structural validation criteria listed below:-
Validate Structural Analysis,
• Static and Fatigue Load Spectrums.
• Material Design Allowable.
Demonstrate strength and durability of Structure adjacent to Wing Fold Mechanism.
• Multi-Slice Lugs on Fold Rib
• Bolted joint between Skins and Fold Rib flange caps.
• Bolted joint between Forward Spar and Fold Rib.
Reduce Design Risk for SDD test box proposed loading.
I was responsible for a small team consisting of designer / stress / and manufacturing
engineers to develop the test articles to meet the following requirements:-
Manufacture of 2 Outboard Wing Test Articles - (1 Static and 1 Fatigue)
Test Articles will be unconditioned and tested at room temperature.
Testing to be completed by LMA.
The design for these two test boxes was completed approved and signed off by
BAE for manufacture before the outboard wing structure manufacture was handed
over to BAE SYSTEMS Canada as a workload reduction measure.
Building Block IPT Design Leader test box F-35C outboard wing.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS F-35B STOVL Design Lead VT SWAT design trade studies.
Responsibilities:-
Lead a small team to undertake a series of `near term‟ STOVL Weight Improvement studies including new substructure and structural layouts using my original CTOL designs as the baseline, on STOVL AFT Fuse, Horizontal Tail and Vertical Tail products, to enable selected design solutions to be incorporated into the SDD phase airframe build as soon as possible, examples of these 30 trade studies can be discussed at interview and the overall effort is shown in figure 9.
To deliver results into Empennage team and AFT Fuse team, and ultimately to John Hoffschwelle (LM) - JSF STOVL Weight Improvement Studies – Lead, to complete `near term‟ studies by March 1st 04 however agreed with John Hoffschwelle that this is CTOL personnel availability dependant, I Lead the Vertical Tail SWAT team consisting of two designers (myself and one other, one weights engineer, one stress engineer, and manufacturing engineer, I generated the original concepts and interfaced with the team, and Aft fuse teams and fuel system teams to turn them into viable solutions, reporting weekly to John Hoffschwelle (LM).
The out come of these studies were design solutions enabling the STOVL F-35 SDD aircraft to be completed and reach a weight within 10% of its target weight. I all so produced the detail design of the primary substructure for the STOVL HT-7, and CTOL vertical tail designs which enabled the mass production manufacturing to be handed to BAE SYSTEMS Woodford site of these structural components. I likewise produced the detail design for the STOVL TVT-7 horizontal tail for the mass production of these structural components to be handed over to BAE SYSTEMS Brough site.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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Figure 9:- STOVL General Weight Reduction Studies.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
STOVL BF-1 VT:- Organisational Structure contributions following SWAT team studies.
STOVL Vertical Tail Phase 2 Layout Organisational Structure
Root Rib
Rib 1
Rib 2A-E
Rib 3
Rib 4A-C
Rudder Support Rib
Spar Brackets
Jamie Smith
Design
Mark Diamond
Malcolm Downie
Ribs
Fwd Shear Fitting
Aft Spar Fitting
Aft Spar
Rudder Hinge 2
Leading Edge Spar
Tip Rib
VT Aft Fuse ICP
VT Leading Edge ICP
VT Tail Cap ICP
VT Rudder ICP
Geoff Wardle
Stuart Reid
Martin Starkie
Roy Winch
Periphery
Vertical Tail - Metallics
Simon Harris
Claire Bridgwood
Spar 1
Spar 2
Spar 3
Spar 4
Spar 5
Barry Green
Neil Doyle
Spars
Outbd Skin
Inbd Skin
Jo Dewhurst
Richard Coddington
Skins
Outbd Fairing
Inbd Fairing
Design
Craig Hannan
Fairings
Frames
Brackets
Seal Integration
Design
Structures
Substructure
Vertical Tail - Composites
Richard Coddington
Jo Dewhurst
Manufacturing Support
Daniel Parry
Vertical Tail
John Holton
Stuart Huskie
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 10:- My responsiblity for Major B1 VT Torsion box substructure component design.
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Design for manufacture of
the Vertical Tail major
substructure : -
Al ribs / spars:
Ti spars and attachment
fittings:
CFC Intermediate spars.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Samlesbury F-35B B-1 aircraft first VT Pre-shipment photo.
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Figure 11:- Vertical tail F-35B B-1 aircraft manufacturing team BAE SYSTEMS Woodford (Left )
and STOVL SWAT team (Right), manufacturing manager far right, Mr G. Wardle VT Trade
Studies design lead second from right.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Samlesbury / Brough F-35 STRUCTURAL CERTIFICATION TEAM.
Figure 12:- Combined Structural Certification Team in front of CTOL structural mock-up aft
fuse and empennage load pad layout designer Mr G. Wardle third from right on second row
back. 18
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Responsibilities in the Combined Structures Certification Team.
I was responsible for developing a structural loading test solution for the rear fuselage and the empennage addressing theses issues, involving extensive liaison with Brough STF and LM:-
What are we trying to simulate?
• Aerodynamic loading
• Inertia loading
• Buffet loading
• Landing and taxiing loads
• Pressurisations (fuel, cockpit, intakes ……)
How sophisticated does the solution need to be?
What standard of test article do we require?
How are we going to support the test article?
How are we going to introduce the loads?
What systems are included in the aircraft for test, bearing in mind this is a flying aircraft subjected to proof loading?
Figure 13:- Proposed structural loading of CTOL
test article from STF Cranfield University MSc
presentation.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The starting point is a series of „unit‟ load cases for various
elements of the structure
• Aerodynamic and Inertia loads
• Different cases for each of the key performance parameters
• Roll rate, pitch rate, vertical „g‟, etc.
• Different cases for different aircraft configurations
• Fuel state, payload, etc.
Carry out an iterative process to establish a load introduction
methodology which matches the Shear Force, Bending Moment
and Torque at pre-determined „key‟ stations
• Due attention to local strength levels at the point of
introduction
Load introduction points are then combined to provide actuator
positions
Responsibilities in the Combined Structures Certification Team cont.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Certain „actuator‟ positions will be replaced by fixed reactions to
restrain the test article in all 6 DoF‟s
• Engine thrust loading
• Undercarriages
• Aircraft hoisting points, etc.
Where it is not a full aircraft, means have to be found to replicate the
interface between the test article and the „aircraft‟
With a knowledge of the positions where the aircraft is going to be
loaded, the maximum load likely to be applied and the likely
deflections the test article will experience, the initial concepts of the
rig can be developed.
Responsibilities in the Combined Structures Certification Team cont.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS/Cranfield University Terrasoar UAS project organisation chart.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
BAE SYSTEMS Airframe Design Lead for Joint Terrasoar Project MALE UAS.
In addition to my F-35 roles and responsibilities from 2003-2006 I
was responsible as the Airframe Design Lead for a joint Cranfield
University BAE Systems Light MALE UAS Project. The objectives
were to design build and fly a MALE UAV to be built from novel
materials and using new techniques to BAE SYSTEMS, this also
formed the MSc group design project. See Cranfield University MSc
section of my LinkedIn profile for full overview.
Figure 14(a):- The resulting airframe was to have
load CFC bearing fuselage skins with minimal
machined metallic components, for a low cost and
low risk conventional UAS layout with the utility of
preliminary flight trials of new FCS for BAE
SYSTEMS autonomous air vehicles.
Figure 14(b):- Final Terrasoar wing as
built configuration with flight controls
installed. 23
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Port outboard wing in Carbon Epoxy first build components as of March 2006.
Figure 15 (a) to (c) :- Terrasoar Outboard wing as
built configuration.
(b)
(c)
(a)
Figure 16 :- Terrasoar wing centre tool.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 17:- Airframe structural build in RTM Carbon Epoxy first mock up mid 2006.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
1. MALE UAV built from Carbon Epoxy using resin infusion for
fuselage, RTM, for wing, at BAE SYSTEMS Manufacturing
Technology Centre Samlesbury.
2. Airframe in final assembly tooling, test articles completed and tested.
3. Systems fit due for completed in July 2006.
4. Role out first week in August 2006 with proof test in second week.
5. Engine ground tests and fit checks completed.
6. Completion of all ground tests including high speed taxi testing due
by last week in August 2006.
7. Flight tests due for completion at the end of September 2006, with
handover to Autonomous Air Vehicle Systems in October 2006.
8. Total project cost £100,000.
9. Production rights handed over to BAE SYSTEMS Australia 2008.
BAE SYSTEMS Samlesbury Terrasoar Project MALE UAS project status 2008.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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IRP Background and Mission requirements capture.
During 1995 LMTAS proposed conversion of “mothballed” F-16A fighters into interim
UCAV‟s to meet a USAF fighter aircraft shortfall in 2005-2015 timeframe by replacing the
wing with a 60ft low aspect ratio planform, and removing the cockpit and pilot systems. This
however would not result in an aircraft suitable for today‟s warfighter as this „Defender‟
would be compromised in speed, non-stealthy and cost $3 to $5 million per jet modification.
Whilst Leading the F-35B SWAT trade studies and Leading the design of the joint Cranfield
University / BAE Systems Terrasoar light UAS team as major part of my MSc studies I
developed an Advanced Interdiction Aircraft (AIA) concept design in both manned and
unmanned variants. This proposal study went from requirements capture H of Q (Table 1
slide 28), through to preliminary design and produced a modular modifiable manned and
unmanned FB-24 / F-35D / A-24 airframe with an estimated cost of $500,000 to $ 1 million
per aircraft, and was a two year study from concept to preliminary design using USAFA
Aerodynamic MDO toolset for analysis, the final report was submitted to the F-35 project
office LM, and ITAR cleared for Cranfield University and involved Catia V5 surface / solid /
and FEA modelling in V5.R10. An overview slide presentation is in the Cranfield University
MSc section of my LinkedIn profile.
The both the FB-24 / F-35D and A- 24 would employ supercruise and stealth to reach time
critical targets, employing the selected mission profile, and with the F-120 VCE would have
loiter capability for targets of opportunity.
CU / BAE / LMTAS CONCEPT STRUCTURAL AND CONFIGURATION DESIGN FOR AIA.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Table 1:- H of Q requirements capture to evaluate the importance of each AIA requirement.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 18:- FB-24 / F35D / A-24 Final down selected configuration side and front views.
18.70
CoG Most Fwd = FS 9.19
CoG Most Aft = FS 10.11
LG = 8.086m
420 53.50
Ground line
16.250 AI View angle
51.60 EOTS Fwd View angle
500 5.945m
13.722m
3.328m
A/C height = 3.79m
Tip back angle
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
30
Tip over angle = 71.90
CoG Most Aft = FS 10.11
CoG Most Fwd = FS 9.19
W = 3.328m
520 15.320
520
19.153m
Figure 19:- FB-24 / F-35D / A-24 Final down selected configuration plan view.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
31 Wing structure Ti Carbon CFC with BMI
inner ply skin
Forward fuselage build
module in carbon PMR-15
Weapons bays Ti SPF/DB
Ceramic composite/ Structural
RAM leading edge flap
Center fuselage
build module in Al
and Ti
Ceramic composite / Structural RAM
leading edge flap
Aft fuselage build
module in Ti
Ceramic / Structural
RAM flaperon
Ceramic composite /
Structural RAM flaperon
Wing structure Ti Ti / Structural RAM loaded
core ruddervators
Figure 20:- FB-24 / A-24 AIA Common Structural integration layout within the IML.
Stbd Main u/c bay
Port Main u/c bay
AI module
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Fig 21:- To reduce wing skin thickness multi spar pitch was used to inhibit skin buckling.
As a Rule of Thumb:- The mass of the skins is
in the order of twice that of the sub-structure.
Therefore where the wing chord thickness is
between 3.9 inches and 11.8 inches, it is more
efficient to increase the number of spars in
order to reduce the skin thickness an hence
reduce weight. Although for highly loaded
combat aircraft spars are used in wings with
root chord thicknesses up to 15 inches in
combination with stiffeners.
N.B. in military combat
aircraft wing ribs are
generally limited to the
weapons carriage and fuel
tank boundary stations.
i.e. long thin panels are more
efficient at resisting buckling
of skins. F/A-24 Concept Advanced fighter aircraft wing structural layout
CFC intermediate spars and rib trade study. 32
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 22:- A-24 Wing metallic sub – structure to Ti boundary joint philosophy.
1.2”
Web to stiffener Outboard Joints.
* Based on 3 x fasteners diameter = 0.1875”
0.34” x 450 Chamfer
r =0.375”
0.4” **
0.2”
0.45” *
1.5”
t = 0.2”
t = 0.1”
Const.
Const.
Al rib Bathtub nested into Ti spar inboard Joints.
* Based on 2 x 0.1875” fasteners diameter + 0.06”
clearance.
** Based on diameter of Eddie bolt installation tool and
footprint of clickbond nutplate.
NB: - Dimensions will vary with web / cap thickness.
0.15”
0.45” *
r =0.16”
0.375” 0.375”
2d
t = 0.12”
0.5
6”
d =0.1875”
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 23:- A-24 Wing composite sub – structure to Ti boundary joint philosophy.
Web to spar stiffener Outboard Joints.
Tab attachment to integral spar stiffener
considered adequate for outboard joints.
Composite rib nested cap Inboard Joints.
Integral stiffener landing would remove the need
for cleated inboard joints reducing parts count.
d =0.1875” d =0.1875”
Ti boundary spar.
Ti boundary spar.
2.5-d 2.5-d
3-d 3-d
Composite rib secured by two
rib cap bolts and two web bolts
through spar stiffener. Composite rib tab secured by
two web bolts through stiffener.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 24:- F-35 Commonality, the fuel system integration also had to meet this target.
My role was to design and integration of a common fuel system within multi variant
airframe structures of the rear fuselage involving interfaces with the Lockheed Martin
wing and Northrop Grumman centre fuselage fuel systems teams. I conducted
successful detailed designs, and structural integration for the small and large bore fuel
lines and fuel tank gas innerting systems, as well as a common fuel dump system for the
CTOL and STOVL variants incorporating a heat shield.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
My role in the BAE SYSTEMS Samlesbury F-35 Subsystems Organisation.
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Subsystems
IPT Lead Brian Cowell
Design Lead
CV Glenn Edmondson
Design Lead
STOVL Ian Lever
Analysis Lead Riz Gulamhussein
4th Site Lead Glenda Dunne
Fokker Elmo WPM Phil Quinn
Business
Mgmnt Lead TBD
Electrical
Group Lead
Steve Brook
Fluid Group
Lead
Colin Ford
Electrical
Group Lead
Nathan Gibbs
Electrical
Group Lead
Nilesh Patel
Fluid Group
Lead
Steve
Reynolds
BM
CV TBD
Horizontal Integration
Electrical
Governance Ian Lever
Fluid Governance Glenn Edmondson
Fluid Group
Lead
Jamie McKay
Analysis Lead Liam Canning
Geoff Wardle
Systems Integration all variants
Design Lead
CTOL Max Kirk
BM
CTOL Rachel Willacy
BM
STOVL Ann Melling
Fluid Group
Lead
Kieran
Bowman
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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BAE SYSTEMS AS&FC MANTIS STRUCTURAL CONFIGURATION DESIGN TEAM
Following the completion of the F-35 design phase and as a result of my design work on the Terrasoar
light UAS I was assigned to the new Autonomous Systems & Future Capability group established
within BAE SYSTEMS to develop the Mantis MALE Multi-role UAS.
At this stage of the only the requirements were known so like Terrasoar the task was Concept design
through to first flight but the time scale was only 18 months.
The basic requirements were as follows:-
Be fully autonomous and all electric flight control system (no hydraulics),
Able to either be transported to a forward operating base or self deploy 66 feet wing span,
Conduct long duration ISR and strike missions with precision guided weapons,
Out-class the US General Atomics Predator A and B aircraft and incorporate advanced cost
reducing manufacturing technologies,
Easily maintained with reduced cost of ownership over manned and competitor unmanned systems
(Global Hawk).
Enabled export productionised examples to markets in Mid and Far east as well as Canada, Europe,
and Australia.
Initial concept and preliminary structural layout design was undertaken by the small Warton team of
which I was a key part, the design of the fuselage was retained by Warton for detailed manufacture, the
wing was subcontracted to BAE SYSTEMS Brough (contracted out to Slingsby for manufacture), the
manufacture of the empennage was also subcontracted to BAE SYSTEMS Brough.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Role – Design and structural layout of Mantis fuselage Spiral 1 and Trade studies for Production aircraft.
BAE SYSTEMS Warton / Preston AS&FC MANTIS MULTI-ROLE UAS.
Conceptual design of the fuselage and structural layout of the forward fuselage:
Manufacturing design of the main load bearing advanced composite fuel tank:
Integration of the forward landing gear and systems:
Detail design and integration of structural components through to manufacture and flight within a concept
demonstration airframe:
Configuration trade studies for the production aircraft for the UK and Export.
On 31st December 2011 I left BAE Systems on VR as part of a mass redundancy program.
Figure 25 :- Mantis Spiral 1 pre flight test at
test site in Australia. November 2009. Figure 26:- Mantis full size model at Farnborough Air Show
38
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
39
Figure 27:- Honeycomb core transition configurations for composite skins.
To reduce the structural weight of skins honeycomb
cores were used reducing skin thickness whilst
maintaining the same structural loading capabilities.
Used for structures les than 2.9” thick.
Ply/Core Edge Tolerance:- The ply and core Edge
Of Part (EOP) curves shall have a line profile
tolerance of 0.200”(±0.100”) unless otherwise
specified on engineering drawing or other applicable
document.
Side CFC skinned honeycomb structures transition at
frame joint zone. (Pictorial representation only). CFC skinned honeycomb frame structures e
closure at side skin mate, wet cleats used for
frame / skin attachment.
Tapered edges can lead to core
crushing issues requiring either a
reduced processing pressure or
friction grips external to the part to
minimise this 20º is design standard.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
40
Figure 28:- Honeycomb core choices for skins based on experience.
Hexagonal Core.
The most common form of core (used for aerospace applications selected).
For soft curvature-(Can be „hot formed‟ to negotiate more severe curvatures.
„NOMEX‟ (Aramid) core is most readily available.
GRP, CFC & Metallic forms are readily available.
Shear load carrying properties are biased towards the „Ribbon‟ or „L‟ direction.
„OX‟ Core (Over Expanded).
„OX‟ core is a hexagonal form which is elongated in the „W‟ direction.
It is used to negotiate pronounced single curvature.
„W‟ shear properties are increased and „L‟ properties are decreased when
compared to Hexagonal core.
(L)
(L)
(L)
(W)
(W)
(W)
„Flex-Core‟.
„Flex-Core‟ exhibits exceptional drape characteristics – making it an ideal
choice for severe compound curvature.
Reduced anticlastic curvature and buckling of cell walls.
Negotiation of tight radii is achieved with minimal loss of load carrying
capability.
It is expensive and therefore should only be selected after a full assessment of
alternatives in the design process.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
28th November 2003 Structural Layout of Composite
Components
41
Figure 29:- Woven Cloth Classifications based on experience.
41
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Overview of my use of FiberSIM in composite design at BAE Systems.
During my employment as a senior design engineer within BAE Systems MA& I have used
FiberSIM I following VITAGY training for the following:-
Ply Producibility: Creation of design stations and zones: Documents (CATIA drawing objects) and
plybook documents: Flat pattern generation analysis and transfer to manufacturing: Darting:
Splicing: Multi skin core batch producibility.
There is insufficient space in this presentation to detail the procedures however a descriptive
narrative of key points is given below. The following four slides give a generic overview of the
information flow and data required to produce a FiberSIM ply and the catia geometric relationships
for document generation.
Laminate creation:- Chart 1:- Prepare the Catia geometry, create a Catia skin which is the part skin
(tool skin): create Catia boundary curve (net boundary): there are four laminate selections in
FiberSIM:- (1) PART-represents tool skin, (MUST have one PART laminate in every model: (2)
ADD SKIN- represents an over-core surface, if the surface topology changes, you must use a new
skin to represent it and create a new laminate of this type: (3) PLY PACK- an organizational tool
that represents a group of plies that are assembled in a separate process and put into the current
composite part definition, which allows the sub elements of the group of plies to be listed within the
current part: (4) UNI LAYER- an organizational tool used to define uni-directional plies that are laid
on the same layer within a layup. The Laminate Form is presented giving the Non-Geometric
Information and Links to Catia Geometry always lock FiberSIM geometry to prevent modification,
and always save the FORM by choosing ACCEPT or YES END, now create the FiberSIM laminate
using CEE+LAMINATE+CREATE enter new / laminate name / part number / laminate type /
geometry status (locked) / skin (tool skin) / boundary (net) / ACCEPT. 42
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
43
Chart 1:-FiberSIM design methodologies Laminate Geometry Relationship.
*FAC *SUR
Skin
*CCV
SKIN GEOMETRY.
*LN *CRV
Extended
Boundary Net
Boundary
CURVE GEOMETRY.
Laminate
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Rosette creation:- Chart 2:- There are three rosette mapping types in FiberSIM which are as
follows:- (1) Standard-this is the most common, ply origin location is mapped by following the
contour of the surface: (2) Translational-zero direction is parallel to an axis of the part: (3) Radial-
zero direction points out in all directions from the center of the surface of revolution. From the
rosette form select:- Display length this is a magnification factor for the rosette spokes: Rosette
type (as shown in chart 2): and Define the rosette zero direction in one of three ways either:-
Another point / Catia axis / or Line or curve through the origin.
Now the rosette can be created:- CEE+ROSETTE+CREATE entre new / Origin (select point on top
of tool skin / Direction key e.g. x / Adjust Display Length e.g. 100/ ACCEPT, and the rosette is
created.
As can be seen from Chart 3 ply generation for producibility analysis requires material definition,
this is the result of selections made from the Materials Database and inputs on the Ply Form.
The FiberSIM Materials Database contains many common composite materials, the limit angle
being the most important parameter for the FiberSIM producibility simulation. Note not all
information in the materials can be viewed in a single Catia view therefore multiple views are
required to view other material parameters.
The Ply Form is used for entering specific orientations as 0/90, 90/0, +/-45 and -/+45, (note
user must type “+/-”) also the user cannot use CTRL-ALT-U. FiberSIM creates a link between
the non-geometric composite data and the 3D geometry through the ply form.
To create the FiberSIM ply:- CEE+PLY+CREATE / new / Set Step 10 / Select Material (e.g. PPG-
PL-3K) / Lock Geometry / run producibility.
44
Overview of my use of FiberSIM in composite design at BAE Systems.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
45
Chart 2:- FiberSIM design methodologies Rosette types and Geometry Relationship.
90°
0°
45°
-45°
Rosette
*PT
Rosette
Origin
ORIGIN GEOMETRY.
*LN *PT *AXIS
*CRV *CCV
Zero
Direction
DIRECTION DEFINITION.
45°
90°
-45°
0°
Standard
45°
-45°
90°
0°
Y
Z
X
Translational
Radial
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
46
Chart 3:-FiberSIM design methodologies Requirements for Producibility analysis.
Tool
Surface
Edge of
Part
Laminate
Skin
Net
Boundary
Rosette
REQUIREMENT. DATA COMES FROM. DEFINED BY.
Ply Origin
Fiber
Direction
Rosette
Origin
Zero
Direction
Material
Definition
Materials
Database Ply
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
From the above ply generation stage ply producibility can now be undertaken:- Click on Flat Net Ply
Boundary / <YES:RUN> (producibility) / <NO:REFUSE> (fiber paths) / <YES:RUN> (flat pattern) /
Change screen to VISTAGY-SPLIT to view flat pattern / Change screen to VISTAGY-SPACE /
<NO:REFUSE> (flat pattern) / <NO:REFUSE> (splice curves) / Save PLY FORM / <ACCEPT> or
<YES:END>.
Sequence and Step in FiberSIM:- The components of a composite part must have an assigned
relationship to each other to define the part‟s layup order. FiberSIM uses SEQUENCE and STEP to
define layup order.
STEP:- is used to define ply order, plies that are laid up at the same time are given the same
step number.
SEQUENCE:- is used to define laminate order , when a new laminate is used to define a new
surface topology it is given a new sequence.
Core sampling conducted in FiberSIM:- Three Core Sample Types are available which are:-
SUMMARY-ply name, orientation, stagger, material, thickness: DETAILED-ply name, orientation,
warp and weft deformation angles: LAMINATE RATING-% symmetry, % laminate balance, %
laminate warpage.
Core sampling is performed via:- CEE+STATION+SAMPLE / Select<none> next to Digitized Points
/ select points / <YES:DONE> / Set Results = SUMMARY / Click on Preform Core Sample / Click
on FWD to toggle through pages of SUMMARY information / <YES:END>.
47
Overview of my use of FiberSIM in composite design at BAE Systems.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Laminate Rating Core Sample.
Symmetry:- Percent of encountered components pairs equidistant from the laminate centerline
that have identical fiber orientations:
Weighted Symmetry:- Percent of encountered components pairs equidistant from the laminate
centerline that have identical fiber orientations and material thickness:
Mechanical Symmetry:- Percent of encountered components pairs equidistant from the
laminate centerline that have identical fiber orientations and material properties:
Laminate Balance:- Percent of laminate at the core sample location that has the same number
of components with positive and negative fiber orientations:
Laminate Warpage:- Percent warpage of the laminate after undergoing a specified temperature
gradient (default is a Δ250°F), the warpage prediction is based on mechanical symmetry of the
ply layup.
Symmetry:- refers to ply order about the laminate centerline or neutral axis. The ply order must
be mirrored about the centerline to have symmetry.
Balance:- refers to the relative number of +45° and -45° plies in the layup. To have balance
there must be the same number of +45° plies as -45°plies.
This has just been a brief overview of creating a laminate, and core sampling for a laminate layup,
there are many aspects of FiberSIM that I have employed during my time at BAE SYSTEMS MA&I.
48
Overview of my use of FiberSIM in composite design at BAE Systems.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
49
Chart 4:- FiberSIM design methodologies Document Geometry Relationship.
TEXT GEOM
Doc
Template
Skin
Extended
Boundary
Net
Boundary
3D ENTITIES. 2D ENTITIES.
Document
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Currently I am conducting a conceptual design study into the application of advanced
manufacturing technology i.e. the PRSEUS technology using NASA/TM-2009-215955 and
NASA/CR-2011-216880 as my structural starting point, and mission adaptive flight control surfaces,
to assess the benefits of these technologies, along with automated assembly when applied to the
wing of a new commercial aircraft. This study for a Future Advanced Technology Aircraft, is a
technical trade study paper for per review and presentation through the AIAA. The baseline aircraft
wing selected is for a CFC twin engine 250-300 seat class point to point aircraft design of
conventional configuration, to determine the structural / weight / and aerodynamic benefits at virtual
trade study level, for commercial aircraft structures to FAR 25 and JAR-25.571, an over view
presentation is given in the current work experience section of my LinkedIn profile (see also chart
5).
Chart 6 covers the study which consists of two phases:- (1) The overall airframe configuration
design and parametric analysis using both classical analysis and the Jet306 / AeroDYNAMIC V2.08
analysis tool set based on my Cranfield MSc: (2) The second is major structural wing component
layout of the airframe initial structure with systems integration, using hand calculations with Catia
V5 GSA modelling for structural sizing. The final design study for both versions of the wing
reference and new build will consist of parametric analysis, initial optimisation and structural layout
and analysis and constitutes a feasibility study proposal to determine the benefits, and constraints
on such an application. Chart 7 shows the research activity dependencies for the project, and Chart
8 shows the design analysis methodology applied. The design philosophy applied to this study has
been Damage Tolerance Design using Safe Life and Fail Safe approaches where applicable. Chart
9 shows basic PRSEUS structural elements which form the basis of the development elements.
My current research and capability maintenance activities in aircraft design.
50
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
51 Basis for my private study the NASA Configuration 1 N+2 Advanced “Tube and Wing” 2025 Timeframe.
Chart 5:- My Catia V5 Design work for the my FATA trade studies 2012 to present.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
IMPERIAL DATA. METRIC DATA.
Wing Span (ft / in) 212 / 5.5 Wing Span (m) 64.8
Length (ft / in) 219 / 10 Length (m) 67.0
Wing Area (sq ft) 4,768.6 Wing Area (sq m) 443.0
Fuselage diameter (in) 234.64 Fuselage diameter (m) 5.96
Wing sweep angle 35° Wing sweep angle 35°
Engine number / type 2 X RR Trent XWB Engine number / type 2 X RR Trent XWB
T-O thrust (lb) 83,000 T-O thrust (kN) 369.0
Max weight (lb) 590,829 Max weight (tonnes) 268.9
Max Landing (lb) 451,940 Max Landing (tonnes) 205.0
Max speed (mph) 391 Max speed (km/h) 630
Mach No 0.89 Mach No 0.89
Range at OWE (miles) 9,321 Range at OWE (km) 15,000
52
TABLE 2:- BASELINE AIRCRAFT DATA TABLE FOR AIAA STUDY.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
53
Chart 6:- My current research activity in aircraft design for the AIAA paper.
The development and application of
advanced structural concepts, and
mission adaptive control surfaces to
commercial aircraft. Estimated at:-
4,680hrs (15 hour weeks over 6 years)
Work book 1:- Composite airframe design
and manufacture incorporating Catia
V5.R20. (exercises vertical tail fighter a/c
design / commercial aircraft vertical tail
design). COMPLETED
Work book 2:- FEA using Catia V5.R20.
(exercises airframe structural component
design and analysis). COMPLETED
Work book 3:- Control surface
kinematics Catia V5.R20. (exercises
airframe flap deployment analysis).
IN WORK
Major structural layout:- Based on
Cranfield MSc Aircraft Engineering
modules using Catia V5.R20 as tool
set.
Defining airframe study concept:-
MSc Aircraft Engineering modules
using Catia V5.R20 as tool set and
AeroDYNAMIC V3.
Major structural loads analysis and
component sizing:- Based on Cranfield
MSc Aircraft Engineering modules
using Catia V5.R20 as tool set.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
54
Chart 7:- Activity dependency for the design trade studies for the FATA paper.
Work book 1:- Composite airframe design
Work book 2:- GSA airframe design
Phase 1:- Baseline composite / metallic
wing box, and wing carry through box
layout design structural component sizing.
Baseline composite / metallic wing
box and wing carry through box
design structural / weight analysis.
Work book 3:- Control surface kinematic
design analysis and sizing.
Phase 2:- Advanced concept composite
PRSEUS wing box, and wing carry through
box layout design structural component
sizing.
Phase 1:- Baseline control surface design,
structural sizing and operational analysis.
Advanced concept composite PRSEUS wing
box and wing carry through box design
structural / weight analysis.
Phase 3:- Future concept full composite
PRSEUS wing box, and wing carry through
box layout design structural component
sizing and weight analysis.
Phase 2:- MAW control surface design
trades, structural sizing, weight and
operational analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
55
Chart 8:- Proposed structural design study methodology for the FATA paper.
Determine airframe
structural loads for
baseline configuration.
Size major structural
components baseline
configuration.
Define wing structural
layout for baseline
configuration.
Design and analyze major
structural components of
baseline configuration
using conventional
materials.
Define wing structural
layout for baseline
configuration with PRSEUS
based technology.
Size structural major
structural components
with PRSEUS based
technology.
Design and analyze
major structural
components of baseline
configuration using
conventional materials.
Compare resultant
structures in terms of
structural integrity, weight,
assembly, manufacture,
cost.
Are there
benefits?
If no modify
conventional
structure.
If yes proceed
to MAW study
with new
structure.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Rohacell
foam core
56
Chart 9:- PRSEUS Structural elements based NASA/TM-2009-215955.
Ply orientations:- Pultruded rod 0º
Each stack : - 7 Plies in +45º / -45º / 0º / 90º / 0º / -45º /+45º
pattern knitted together. Percent by fiber area weight
(44/44/12) using (0º/45º/90º) nomenclature.
All detailed parts are constructed from AS4 standard
modulus (33million psi) carbon fibers DMS 2436 Type 1
Class 72 (grade A) and HexFlow VRM 34 resin.
Rods are Toray unidirectional T800 fibres with a matrix of
3900-2B resin.
The preforms were stitched together using a 1200 denier
Vectran thread, and infused with a DMS2479 Type 2 Class 1
(VRM-34) epoxy resin (all dimensions in inches).
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The objective of this work is toolset skills enhancement with the Catia V5.R20 GSA system, below
are the limitations of the Catia V5 R20 FEA toolset which need to be considered when applying this
toolset:-
a)Material Linearity:- In Catia, it is assumed that the stress and strain are linearly related through
Hook‟s law, therefore metals should not be loaded into the plastic deformation region, and rubber
type materials cannot be analyzed by this toolset.
b)Small Strains:- The strains used in Catia are the infinitesimal engineering strains which are
consistent with the limitations above in (a). As an example, problems such as crushing of tubes
cannot be handled by this software.
c)Limited Contact Capabilities:- Although Catia is capable of solving certain contact problems,
they must be within the limitations noted above in (a) and (b). Furthermore, no friction effects can
be modeled by the software.
d)Limited Dynamics:- The transient response in Catia V5 is based on model superposition.
Therefore a sufficient number of modes have to be extracted in order to get good results. The direct
integration of the equations of motion are not available in this version.
e)Beam and Shell Formation:- In these elements shear effects are neglected. Therefore, the
results of thick beams and shells may not be very accurate although not an aerospace issue.
Although these issues seem severe limitations most basic mechanical design problems can be
analyzed using this tool set as such problems are governed by linear elastic analysis.
57
Catia V5.R20, FEA Skills toolset enhancement evaluating system limitations.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
There are two types of solid element available in Catia V5.R20 Generative Structural Analysis
which are Linear and Parabolic. Both are referred to as tetrahedron elements shown below.
Limited Hex elements are also available. As are Linear and Parabolic shell elements as well are
limited QUAD elements.
58
Solid Tetrahedron Elements.
Linear. Parabolic.
The Linear tetrahedron elements are faster computationally but less accurate. On the other hand,
the Parabolic elements require more computational power but lead to more accurate results.
Parabolic elements have the very important feature that they can fit curved surfaces better than
Linear elements. In Catia V5 solid machined parts are generally analyzed using solid elements,
where as thin walled and sheet structures are analyzed using shell elements. Linear triangular
shell elements have three nodes each having six degrees of freedom, i.e. three translations and
three rotations, the thickness of the shell has to be provided as a Catia input. As is the case with
the solid tetrahedron elements the Parabolic elements are more accurate.
Linear
18 DoF.
Parabolic
36 DoF.
Sheet Triangular Shell Elements.
Catia V5.R20, FEA Skills toolset enhancement evaluating system components .
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The element “size” and “sag” icons appear on each part on entering the Analysis & Simulation >
Generative Structural Analysis toolset. The concept of element size is self explanatory, i.e. the
smaller the element size the more accurate the results at the expense of longer computation time
and processor power. The “sag” is a unique Catia term, in FEA the geometry of a part is
approximated with elements, and the surface of the part and FEA approximation of a part do
exactly coincide. The “sag” parameter controls the deviation between the two, therefore the smaller
the “sag” value generally the better the results.
Catia V5‟s Finite Element Analysis module is geometrically based, therefore the boundary
conditions cannot be applied to nodes and elements. The boundary conditions can only be applied
at the part level. On entering the Generative Structural Analysis workbench, the parts are
automatically hidden. Therefore, before boundary conditions can be applied, the part must be
brought back into the visual working space, and this was carried out by pointing the cursor to the
top of the tree, the Links Manager.1 branch, right-clicking, selecting Show. At this point both the
part is visible and the mesh is superimposed on it, the latter was hidden by pointing the cursor at
Nodes and Elements and right-clicking Hide. This has been the methodology for each worked
example in this presentation, figures 30,32,34,38,40, and 37 show the parts, with constraints and
loading, where figures 31, 33, 36, 39,and 41 show the total displacement magnitude analysis and
Von Mises stress analysis with maximum and minimum values in each case. The three analysis
examples in this presentation form a small part of my Workbook two which is leading into complex
studies of airframe structures.
59
Catia V5.R20, FEA Skills toolset enhancement evaluating system methods.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Four examples of these ongoing studies are given here:-
1)Bearing Shaft Assembly using Analysis Connections:- Problem statement:- The assembly
shown in figure 30 consist of a shaft of 1” diameter and length 6”, and two bearings with dimensions
as shown. All parts are made of aluminum with E=10.15E7 psi and v = 0.346. The bottom faces of
the bearings are clamped and the shaft is subjected to a total downward load of 100lb distributed
on its surface. The objective of this analysis was to predict stresses and deflections in the structure.
Full stress report was produced the results are shown in figures 31(a) and 31(b).
2)Tensile Test Specimen Assembly:- Problem statement:- The assembly consisted of two steel
pins (1”diam x 3” long) and an aluminum block (10”x 4”x1”). The constrained and loaded assembly
is shown in figure 32. The end faces of the bottom pin are clamped, and the end faces of the top
pin are given a displacement of 0.01” (0.254mm) causing the block to stretch. The objective was to
determine the force necessary to cause this deflection and predict the stresses in the structure, for
this analysis Parabolic Tetrahedron elements were used for this analysis. A full stress report was
produced, the results are shown in figures 33(a) and 33(b).
3)Spot Weld Analysis:- Two sheets of made of steel having a thickness of 0.03” are spot welded
together at four dotted points as shown in figure 34. The edge AB of the bottom plate is clamped
and the edge CD of the top L section is loaded with a 10lb force. All the dimensions shown are in
inches. The objective was to use Catia V5.R20 Generative Structural Analysis to predict the
stresses in these parts. Linear Triangular elements were used for this analysis. A full stress report
was produced, the results are shown in figures 35 and 36.
60
Catia V5.R20, FEA Skills toolset enhancement worked examples.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
4) Analysis of a fastened assembly:- This assembly consisted of two plates, clamped together
with a preloaded steel bolt. One plate was loaded causing the bending of the entire structure.
The objective of this analysis was to predict the stresses and deflections to which the assembly
was subjected. The top plate was 1” by 1” square with a thickness of 0.125”: the bottom plate
was 1” by 2” with a thickness of 0.125” each had a 0.125” radius hole 0.5” from the trailing edge
as shown in figure 37. The bolt had a shaft radius of 0.125” and length 0.4”, and a head radius
of 0.2” and thickness of 0.1”. The assembly was constructed using Coincidence constraint's and
the material steel was applied. The resultant assembly being meshed, restrained, and contact
connected as shown in figure 38, then a tightening force of 50lbs was applied to the bolt
tightening connection, analysis was then undertaken of displacement, and Von Mises stress in
the assembly, the results are shown in figures 39(a) and (b). Subsequently a distributed load of
100lbf was applied to the leading edge of the lower plate as shown in figure 40 in the Z direction
as a distributed force, and the assembly was re-analysed for displacement and Von Mises
stress values, the results are shown in figures 41(a) and (b).
The final outcome of this workbook will ultimately be the analysis of metallic and composite wing
structures in support of my wing research program, and the method for composite part evaluation
will be based on the procedure overview shown in figure 42, checking against a NASTRAN
component level evaluation.
61
Catia V5.R20, FEA Skills toolset enhancement worked examples.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
62
Figure 30:- Example my Catia V5.R20 FEA:- bearing assembly exercise load and constraints.
2 inch 1 inch
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 31:- My Catia V5.R20 aluminum bearing beam assembly analysis.
Figure 31(a) :- Total displacement magnitude
analysis of the bearing beam assembly.
Maximum deflection = 0.000881691”
Minimum = 0”
63
Figure 31(b) :- Von Mises Stress (nodal
values) analysis of the same bearing beam
assembly. Maximum stress = 1902.12 psi,
Minimum stress = 17.7862 psi.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
64
Figure 32:- Example my Catia V5.R20 FEA:- tensile specimen exercise load and constraints.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
65
Figure 33:- My Catia V5.R20 two material tensile test specimen assembly analysis.
Figure 33(a) :- Total displacement magnitude
analysis of the tensile specimen assembly.
Maximum deflection = 0.01” Minimum = 0”in
the pins and Maximum deflection of 0.00851”
Minimum = 0.00148” in the test block.
Figure 33(b) :- Von Mises Stress (nodal values)
analysis of the same tensile specimen
assembly. Maximum stress = 50732.6 psi, in the
top pin Minimum stress = 51.8327 psi in the
test block.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
66
Figure 34:- My Catia V5.R20 FEA Spot welded sheet assembly problem structure.
C
D
A
B
5 in
12 in
3 in
4 in
2 in
2 in
2 in
2 in
2 in
C
D
A
B
5 in
12 in
3 in
4 in
2 in
2 in
2 in
2 in
2 in
1in
10 in
Sheet Material = Steel:
Sheet Thickness = 0.03 inch:
Top L section loaded edge C-D:
Bottom plate clamped edge A-B.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
67
Figure 35:- Example my Catia V5.R20 FEA:- Spot welded sheet exercise load and constraints.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
68
Figure 36(a) :- Total displacement magnitude
analysis of the spot welded sheet assembly.
Maximum deflection = 1.38369” Minimum = 0”.
Figure 36(b) :- Von Mises Stress (nodal
values) analysis of the spot welded sheet
assembly. Maximum stress = 35325.8psi,
Minimum stress = 265.515psi. Maximum
stress was in the weld line as expected.
Figure 36:- My Catia V5.R20 Sheet steel spot welded assembly analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
69
Figure 37:- Example my Catia V5.R20 Bolted assembly components for analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
70
Figure 38:- Example my Catia V5.R20 Bolted assembly constrained and preload for analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
71
Figure 39:- My Catia V5.R20 Bolted assembly preload analysis.
Figure 39(b) :- Von Mises Stress (nodal
values) analysis of preloaded bolted
assembly. Maximum stress = 1818.98psi,
Minimum stress = 0.149288psi. Maximum
stress the bolt as expected.
Figure 39(a):- Total displacement magnitude
analysis of the preloaded bolted plate
assembly. Maximum deflection = 3.35588e-
005” Minimum =1.0” the max value being in
the bolt as expected.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
72
Figure 40:- Example my Catia V5.R20 Bolted assembly constrained and preload for analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
73
Figure 41:- My Catia V5.R20 Bolted assembly preload with added end load analysis.
Figure 41(a) :- Total displacement
magnitude analysis of the loaded
bolted plate assembly. Maximum
deflection = 0.0448786” Minimum =
1.0” the max value being in the lower
plate edge as expected.
Figure 41(b) :- Von Mises Stress (nodal
values) analysis of preloaded bolted
assembly. Maximum stress = 39003.4psi,
Minimum stress = 82.218psi. Maximum
stress the bolt region as expected.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
74
Figure 42:- Catia V5.R20 composite structural analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
CATIA V5 R20 Composite design toolset skills enhancement training.
There are two composite design products within Catia V5 Composite Work Bench which are
Composites Engineering Design (CPE) and Composites Design for Manufacturing (CPM) and
these are outlined below see My Composite Capability Maintenance LinkedIn presentation.
The Composites Engineering Design (CPE) product provides orientated tools dedicated to
the design of composite parts from preliminary to engineering detailed design. Automatic ply
generation, exact solid generation, analysis tools such as fiber behavior simulation and
inspection capabilities are some essential components of this product. Enabling users to embed
manufacturing constraints earlier in the conceptual design stage, this product shortens the
design-to-manufacture period.
The Composites Design for Manufacturing (CPM) product provides process orientated tools
dedicated to manufacturing preparation of composite parts. With the powerful synchronization
capabilities, CPM is the essential link between engineering design and physical manufacturing,
allowing suppliers to closely collaborate with their OEM‟s in the composite design process. With
CPM, manufacturing engineers can include all manufacturing and producibility constraints in the
composites design process.
The objective of this self study is to develop and enhance the skills set in the application of the
Catia V5 R20 Composite Engineering Design (CPE), and Composite Design for Manufacture
(CPM), post Cranfield MSc and BAE SYSTEMS composite design training modules.
The complete CPE / CPM design studies including these exercises, and VT spars and skins as
well as project studies constitutes Workbook 1 and the shortened composite design capability
presentation to be added to my profile.
75
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Laminates generated without balanced plies about the Neutral axis will warp during processing.
During the cure cycle a Thermosetting Epoxy resin system hardens (between 120ºC and 140ºC).
When cooling from its maximum processing temperature of 175ºC the resin contracts
approximately 1000 times more than the Fibre, and this mechanism induces warpage of the
Laminate unless the layup is fully balanced about its Neutral axis which can either be a central
plane or an individual ply layer, as shown in figure 43.
76
CT1:- Introduction to Composite Design Balanced Composite Laminate.
Linear Expansitivity (of Fibres) = 0.022
x10^-6 (approximately).
Linear Expansitivity (of Resin) = 28
x10^-6 (approximately).
45º
N A
45º
-45º
-45º
90º
90º
0º
0º
Balanced ply around NA (Neutral Axis) plane. No ply
angle more than 60º separation angle between
layers.
Figure 43:- Expansitivity difference between fibre and resin matrix illustrating
requirement for balanced ply layups around the Neutral axis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The ability to create balanced ply laminates is vital to the construction of real world composite
components and can be achieved for simple laminates using the balanced laminate icon and
selecting the ply group as shown in figure 44. Then reorder the ply sequence so that no adjacent
ply is orientated at angles greater than 60º to the next, in real world situations this requires a more
complex laminate than these simple toolset training examples as we shall see in the tail spar and
cover skin exercises, to react real world loading conditions, this operability is better achieved by
creating a ply layup table in excel and importing it into to Catia V5 model and this is covered later in
Workbook 1. The resulting laminate for this exercise is shown in figure 45 and the numerical
analysis is shown in table 3.
There is also a ply facility in CPE called Plies Symmetry Definition this is used to move a laminate
from one side of a tool surface to the other. In order to use this first crate a symmetry plane about
which the plies will be generated then create a reference surface for the symmetric plies to be
generated from then select the direction about which the symmetric ply is to be generated, select
the ply or ply group to generate the symmetry. This was investigated and will be applied when
appropriate in this study but should not be mistaken as balanced laminate tool.
The rest of the work conducted herein will use balanced ply laminates either using Create
Symmetric Plies method or from balanced ply layup tables generated in excel and imported into the
model.
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CT1:- Introduction to Composite Design Balanced Composite Laminate.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
78
Figure 44:- Example of my CPE methodology for balanced CFC laminate design.
A balanced ply laminate can be
produced by selecting the ply group
and the balanced ply icon.
Subsequently the ply sequence can be manually reordered so
that adjacent plies are not orientated more than 60º to each
other, manually renumbering the sequence and the ply (use
reorder children).
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
79
P3 = -45°
P4 = 0°
P5 = 0°
P6 = -45°
P7 = 90°
P8 = 45°
P1 = 45°
P2 = 90°
Detail A
Detail A
Tool face geometry
Laminate Ply Stack
Fig 45 (b):- Composite part laminate lay-up.
Figure 45:- My CPE design of a balanced composite laminate from WB1.
Fig 45 (a):- Final Composite Part Build.
79
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
80
Table 3:- Example of my balanced laminate Numerical Analysis.
PlyGroup Sequence Ply/Insert/Cut-Piece
Name Material Direction Area (in2) Volume (in3)
Volumic
Mass(lb) Aerial Mass(lb)
Center Of
Gravity - X(in)
Center Of Gravity
- Y(in)
Center Of Gravity
- Z(in) Cost
Plies Group.1 Sequence.1 Ply.1 U174_T800 45 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.2 Ply.2 U174_T800 90 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.3 Ply.3 U174_T800 -45 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.4 Ply.4 U174_T800 0 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.5 Ply.5 U174_T800 0 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.6 Ply.6 U174_T800 -45 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.7 Ply.7 U174_T800 90 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
Plies Group.1 Sequence.8 Ply.8 U174_T800 45 100 0.511811 0.0277355 0.0412477 -5 -1.26E-15 0 0.299419
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Fig 46:- Example of my CPE work e.g. Transition Zones part build model and tree.
81
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
82
Fig 47(a/b):- Example of Transition Zone completed part and ply stack-up.
(X)
(Y)
(Z)
Figure 47(a) Final Transition Zone Part Geometry.
P10 = 0º
P9 = -45º
P8 = 45º
P7 = 90º
Detail A
Detail A
Reference surface
90º Ply drop 0º Ply drop
0º Ply drop
90º Ply drop
-45º Ply drop
45º Ply drop
Figure 47(b) Ply stagger in transition zone.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
83
PlyGroup Sequence Ply/Insert/Cut-Piece
Name Material Direction Area(in2) Volume(in3)
Volumic
Mass(lb) Aerial Mass(lb)
Center Of Gravity -
X(in) Center Of Gravity -
Y(in) Center Of Gravity -
Z(in) Cost
Plies Group.1 Sequence.1 Ply.1 GLASS 90 90 0.637795 0.0460836 0.038403 4.5 5 0 0.497496
Plies Group.1 Sequence.2 Ply.2 GLASS 0 95 0.673228 0.0486438 0.0405365 4.75 5 0 0.525134
Plies Group.1 Sequence.3 Ply.3 GLASS 0 100 0.708661 0.051204 0.04267 5 5 0 0.552773
Plies Group.1 Sequence.4 Ply.4 GLASS -45 105 0.744094 0.0537642 0.0448035 5.25 5 0 0.580412
Plies Group.1 Sequence.5 Ply.5 GLASS 45 110 0.779528 0.0563244 0.046937 5.5 5 0 0.60805
Plies Group.1 Sequence.6 Ply.6 GLASS 90 115 0.814961 0.0588847 0.0490705 5.75 5 0 0.635689
Plies Group.1 Sequence.7 Ply.7 GLASS 90 150 1.06299 0.0768061 0.0640051 7.5 5 0 0.82916
Plies Group.1 Sequence.8 Ply.8 GLASS 45 150 1.06299 0.0768061 0.0640051 7.5 5 0 0.82916
Plies Group.1 Sequence.9 Ply.9 GLASS -45 150 1.06299 0.0768061 0.0640051 7.5 5 0 0.82916
Plies Group.1 Sequence.10 Ply.10 GLASS 0 150 1.06299 0.0768061 0.0640051 7.5 5 0 0.82916
Table 4:- CT2:- Example of Transition Zones Numerical Analysis.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
84
Fig 48(a)/(b):- Updated laminate and ply stack Limit Contour with Staggered Values.
Figure 48(a) Updated Laminate Configuration
Figure 48(b) Updated Ply Stack Configuration
New ply stagger
from Curve C
1a
New ply stagger
from Curve C
2a
New ply stack
from Curve C 1a
New ply stack
from Curve C 2a
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 49:- Example of my CPE work e.g. Limit Contour with Staggered Values.
85
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Below are the ply layup guidelines I used in the design of composite parts at BAE Systems.
Align fibres to principle load direction:
The lay-up ply orientations must be balanced about the mid-plane (neutral axis) of the laminate, as so
to avoid distortion during cure:
Outer plies shall be mutually perpendicular to improve resistance to barely visible impact damage:
Overlaps and butting of plies:
U/D, no overlaps, butt joint or up to 2mm gap:
Woven cloth, no gaps or butt joints, 15mm overlap:
No more than 4 plies (0.125mm per ply) of a single orientation in one stack within a laminate:
A maximum of 67% of any one orientation shall exist at any position in the laminate:
4 plies separation of coincident ply joints rule (ply stagger rules):
Changes in the laminate thickness should occur evenly with a taper rate of 1 in 20 in the principal load
direction. This can be reduced to 1 in 10 in the traverse direction:
All ply drop-offs to be internal and interleaved with full plies:
Internal corner radii of channels
„t‟ < 2.5mm, radius = 2t or 3.0mm whichever is greater
„t‟ 2.5mm, radius = 5.0mm
While co-curing honeycomb sandwich panels, beware of ply quilting during cure over the core area,
need for core stabilisation and reduced cure pressures.
Minimum skin thickness over honeycomb sandwich panels to prevent moisture ingress to be
respected (typically 1mm for UD and 1.5 for cloth). Use of surface films on thin skin panels such as
Tedlar can be considered.
Composite ply layup guidelines from BAE Systems MA&I practice detailed in WB1.
86
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
This is the data required on all 2-D
composite drawings and this is followed
in Design Workbook 1 and the research
project.
Ply Rosette
Stagger Index
Ply Profiles
Lay-up Datum
Honeycomb Core
Profile
Ribbon Direction
Drawing from Cranfield University MSc
presentation.
87
Figure 50:- 2-D drawing annotation based on BAE Systems practice.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Required components of a
composite part 2-D drawing.
Lay-up Table
Assembly Details
Notes
Drawing from Cranfield
University MSc presentation.
Figure 51:- 2-D drawing annotation based on BAE Systems practice.
88
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
89
Figure 52:- Type 1 ply lay up table for simple detail parts BAE Systems practice.
N.B.:- Drawing and layup table from Cranfield University MSc presentation.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
90
Figure 53:- Type 2 ply lay up table for multi-island parts BAE Systems practice.
N.B.:- Drawing and layup table from Cranfield University MSc presentation.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 54:- 2-D Laminate thickness variation BAE Systems practice.
91
0° 90° 45°
135°
" t "
LEGEND:
1,5 1,5 1,0 3,0
7,0
2,5 1,5 2,0 3,0
9,0
3,0 2,0 2,5 3,0
10,5
2,0 2,0 2,0 4,0
10,0 1,5 1,5 1,0 2,0
6,0
4,5 1,5 2,0 3,0
11,0
5,0 2,0 4,5 4,5
16,0
Detail „A‟
„B - B‟
THICKNESS VARIATION
FROM 4mm TO 22mm.
See Detail „A‟
N.B.:- Drawing and layup table from Cranfield University MSc presentation.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
92
Figure 55:- Weight reduction by of ply drop off design modifications.
PLY DROP OFFS: - 1:20 SPANWISE / 1:20 CHORWISE.
(More usual to have symmetrical ply drop off e.g. all 1:20).
PLY DROP OFFS: - 1:20 SPANWISE / 1:10 CHORDWISE.
(Although in some cases un-symmetrical ply drop off e.g. 1:20 in
direction of principal stress and 1:10 in the transverse direction).
WEIGHT REDUCTION OF COMPOSITE
WING COVER SKINS.
N.B.:- Drawing from Cranfield University MSc presentation.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
This is an overview of the considerations made in joint design for the Terrasoar and other projects,
it is important to evaluate the advantages and disadvantages of both bolted and bonded
construction methods.
The advantages of bolted assembly are:-
1)Reduced surface preparation:
2)Ability to disassemble the structure for repair:
3)Ease of inspection.
The disadvantages of bolted assembly are:-
1)High stress concentrations:
2)Weight penalties incurred by ply build ups, and fasteners:
3)Cost and time in producing the bolt holes, and inspection for delamination's:
4)Assembly time.
Corresponding issues for bonded assembly are set out below.
The advantages of bonded assembly are:-
1)Low stress concentrations:
2)Small weight penalty:
3)Aerodynamically smooth.
93
Design considerations I used in composite structural assembly joint design.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The disadvantages of bonded assembly are:-
1) Disassembly, in most cases some part of a bonded structural assembly will need to be bolted
instead of bonded to permit access for repair and inspection. An example is the Typhoon
wing structure where the bottom skin is co-bonded to the structural spars, and top skin is
bolted to the same spars, permitting access from one side:
2) Surface preparation, and bond line inspection for porosity even in co-bonded joints using C-
scan ultrasonic inspection, resulting increased costs and time:
3) Need to design for bolted repair access:
4) Environmental degradation due to water absorption leading to degradation in hot / wet
condition, solvent attack:
5) Need for increased qualification testing effort to establish design allowables.
In the case of the vertical tail exercise I created for Workbook 1 based on A-24 studies, I used
bolted construction selected primarily because of the requirement to quickly, inspect, repair, or
replace damaged structural components within a first line servicing environment. For the purpose of
that exercise the external formation light bolted installation was omitted to reduce complexity of the
design and for ITAR. In the vertical tail component and assembly models bolt datum positions were
shown as points and vectors, as was the standard in my BAE Systems MA&I design practice.
94
Design considerations I used in composite structural assembly joint design.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Co-Curing:- This is generally considered to be the primary joining method for joining
composite components the joint is achieved by the fusion of the resin system where two (or
more) uncured parts are joined together during an autoclave cure cycle. This method minimises
the risk of bondline contamination generally attributed to post curing operations and poor
surface preparation. But can require complex internal conformal tooling for component support.
Co-Bonding:- The joint is achieved by curing an adhesive layer added between a co-cured
laminate and one or more un-cured details. This also requires conformal tooling as shown in
figure 56, and as with co-curing the bond is formed during the autoclave cycle, this method was
used on Eurofighter Typhoon wing spars which were co-bonded to the lower wing cover skins,
and proposed for the F-35B VT lower skin stringers in SWAT trade studies. Care must taken to
ensure the cleanliness of the pre-cured laminate during assembly prior to the bonding process.
Secondary Bonding:- This process involves the joining of two or more pre-cured detail
parts to form an assembly. The process is dependent upon the cleaning of the mating faces
(which will have undergone NDT inspection and machining operations). The variability of a
secondary bonded joint is further compounded where „two part mix paste adhesives‟ are
employed. Generally speaking, this is not a recommended process for use primary structural
applications.
95
Design considerations for adhesive bonded joints detailed in WB1.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
96
„FILM‟ ADHESIVE
(BSL.322)
„CLEAVAGE‟ FILLED WITH
UN-CURED CFC WEDGE
RELEASE AGENT
PRE-CURED
CFC SKINS
UN-CURED „Z‟ & „C‟
SPAR ELEMENTS
UN-CURED „Z‟ & „C‟
SPAR ELEMENTS
CONFORMABLE TOOLING SHOWN THUS:
Figure 56:- Co-Bonded composite spar manufacture detailed in WB1.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Composite bolted joint design rules:-
1)Design for bolt bearing mode of failure:
2)Counter sink (CSK) depth should not exceed 2/3 of the laminate thinness if required fill
laminate artificially with syntactic core (if design rules permit e.g. not permitted for USN, or
USMC):
3)Minimum bolt pitch is 4D for sealed structures such as fuel tanks, and 6D for non sealed
structures (where D is the bolt diameter):
4)Use only Titanium alloy or stainless steel fasteners to minimise corrosion risk see table 4:
5)Use a single row of fasteners for non sealed structures and a double row for sealed structures
such as fuel tanks:
6)Minimum fastener edge distances are:-
3D in the direction of the principal load path see figure 57:
2.5D transverse to the principal load path see figure 57:
97
Design considerations composite structural bolted joint design detailed in WB1.
Figure 57 fastener edge distances.
2.5xD 3.0xD
4.0 x D
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Shims are used in airframe production to control structural assembly and to maintain aerodynamic
contour and / or structural alignment. With composite joints the allowable unshimmed gaps are only
¼ as large as those for an similar metallic structural joints. Therefore, the assembly of composites
generally require more extensive use of shims than comparable metal components.
Engineering can reduce both cost and waste by controlling shim usage through design and
specifications. Design can control where to shim: what the shim taper and thickness should be:
what gap to allow: and whether the gap should be shimmed or pulled up with fasteners.
Shim materials currently available are:-
1)Solid shims:- titanium: stainless steel: precured composite laminates: etc.
2)Laminated (or peelable) shims {with a laminate thickness of about 0.003” (0.0762mm) ±0.0003”
(0.00762mm)}
Laminated titanium shims:
Laminated stainless steel shims:
Laminated Kapton shims.
3)Moldable shim, which is a cast – in – place plastic designed for use in filling mismatches between
metal or composite parts. It can be used at any location to produce custom mating molded surfaces
examples are given in Workbook 1.
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Composite structural mechanically fastened joint design shim guidelines.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
99
FASTENER
MATERIAL / COATING COMPATABILITY
• Monel. Marginally acceptable.
• Alloy Steel.
• Silver Plating.
• Nickel Plating.
• Chromium Plating.
Excellent compatibility and are
recommended for use in CFC structures
• Cadmium Plating.
• Zinc Plating.
• Aluminium Coating.
Not compatible, and will deteriorate
rapidly when in intimate contact with CFC.
• Titanium Alloy.
• Corrosion Resistant Steel.
Excellent compatibility and are
recommended for use in CFC structures
• Al. Alloys.
• Magnesium Alloys.
Not compatible
Not compatible
Table 5:- Galvanic compatibility of fastener materials and coatings.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
100
The use of carbon composites in conjunction with metallic materials is a critical design
factor :-
Improper interfacing can cause serious corrosion :
Problem for metals e.g. Fasteners:
This corrosion problem is due to the difference in electrical potential between some of the
materials widely employed in the aircraft industry, and carbon:
When in contact with carbon and in the presence of moisture (electrolyte), anodic materials
will corrode sacrificially (galvanic corrosion).
Corrosion prevention methods for aluminium alloys (see also fig 58):-
1) Prevent moisture ingress:
2) Prevent electrical contact carbon / metal:
3) Anodise aluminium parts:
4) Seal in accordance with project specifications:
5) Protective ply of inert cloth (glass) between contact surfaces extending 1” beyond edge on
metal part (as required as drill breakout material), and protective sealant (Polysulphide)
„Interfay‟.
Design against metallic corrosion in contact with carbon fibre composites.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
101
Figure 58:- Corrosion prevention methods for carbon fibre structures.
EPOXIDE PRIMER (15 to 25 Microns THICK)*
ANODIC TREATMENT*
Pu. VARNISH or EPOXIDE PAINT FINISH (ONE COAT)*
Al ALLOY COMPONENT
POLYSULPHIDE „INTERFAY‟ SELANT
EPOXIDE PRIMER**
GRP (As required as a „Drill
Breakout‟ material.)**
CARBON FIBRE COMPOSITE
* = Applied over the entire Al component.
** = Applied over the entire CFC
component – or a minimum of 5mm
beyond the contact area.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Impact damage:- Impact damage in composite airframe components is a major concern of
designers and airworthiness regulators. This is due to the sensitivity of theses materials to quite
modest levels of impact, even when the damage is almost visually undetectable. Detailed
descriptions of impact damage mechanisms and the influence of mechanical damage on residual
strength can be found in ref 6. Horizontal, upwardly facing surfaces are the most prone to hail
damage and should be designed to be at least resistant to impacts in the order of 1.7J (This is a
worst case energy level with a 1% probability of being exceeded by hail conditions). Surfaces
exposed to maintenance work are generally designed to be tolerant to impacts resulting from tool
drops (see figure 59). Monolithic laminates are more damage resistant than honeycomb structures,
due to their increased compliance, however if the impact occurs over a hard point such as above a
stiffener or frame, the damage may be more severe, and if the joint is bonded, the formation of a
disbond is possible. The key is to design to the known threat and incorporate surface plies such as
Kevlar or S2 glass cloth. Airworthiness authorities categories impact damage by ease of visibility to
the naked eye, rather than by the energy of the impact: - BVID barely visible impact damage and
VID visible impact damage are the use to define impact damage. Current BVID damage tolerance
criterion employed on the B787 is to design for a BVID damage to a depth of 0.01” to 0.02” which
could be caused by a tool drop on the wing, and missed in a general surface inspection should not
grow significantly to potentially dangerous structural damage, before it is detected at the regular
major inspection interval. This has been demonstrated through a building block test program, and
the wing structures so inflicted have maintained integrity at Design Ultimate Load (DUL). These
design criteria are critical airworthiness clearances ACJ 25.603 and FAA AC20.107A (Composite
Aircraft Structures).
102
Composite impact design guidelines detailed in WB1.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
103
Figure 59:- Structural damage risks to composite structures e.g. the wing.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
104
CFRP Composite are poor conducting materials and have a significantly lower conductivity than
aluminium alloys, therefore the effects of lightening strikes are an issue in composite airframe
component design and a major issue for airworthiness certification of the airframe. The severity of
the electrical charge profile depends on whether the structure is in a zone of direct initial
attachment, a “swept” zone of repeated attachments or in an area through which the current is
being conducted. The aircraft can be divided into three lightening strike zones and these zones for
the wing with wing mounted engines is shown in figure 60, and can be defined as follows:-
Zone 1:- Surface of the aircraft for which there is a high probability of direct lightening flash
attachment or exit: Zone 1A- Initial attachment point with low probability of flash hang-on, such
as the nose: Zone 1B- Initial attachment point with high probability of flash hang on, such as a
tail cone.
Zone 2:- Surface of the aircraft across which there is a high probability of a lightening flash
being swept by airflow from a Zone 1 point of direct flash attachment: Zone 2A- A swept-stroke
zone with low probability of flash hang-on, e.g. a wing mid-span: Zone 2B- A swept-stroke zone
with high probability of flash hang-on, such as the wing trailing edge.
Zone 3:- Zone 3 includes all of the aircraft areas other than those covered by Zone 1 and Zone 2
regions. In Zone 3 there is a low probability of any direct attachment of the lightening flash arc,
but these areas may carry substantial current by direct conduction between some Zone1or Zone
2 pairs.
Methods of lightening strike protection for military and commercial aircraft wings are shown in figure
66.
Composite lightening strike design guidelines detailed in WB1.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
105
Zone 3 Indirect effects.
Zone 2 Swept stroke.
Zone 1 Direct strike.
Lightening Strike
Zones on an
aircraft with wing
mounted engines.
Figure 60:- Lightening strike risks to composite transport wing with podded engines.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
106
Figure 61:- Lightening strike protection of composite wing structures.
Copper grid
Fig 61(a) Aluminum foil EAP.
Fig 61(b) Copper strip Eurofighter Typhoon. Fig 61(c) Copper mesh grid Boeing 787.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
There are metallic structural components employed in the AIAA design project designed by myself
these include the wing ribs which are designed to be produced as double sided machining's from
Aluminium Lithium alloy by 5 axis high speed machining, and figures 62 to 66 illustrate the
machining methods and standards applied in all machined component design. The following are
examples:- figures 67 to 70 are exercises in support of the design activity. Sheet metal design is
shown in charts 6 and 7 and figure 71 to 73 and are sheet metal design worked examples to
maintain capability.
The one of the most effective weight reduction features for the all metallic aircraft wings has been
the adoption of large scale five axis high speed machining of many structural components
previously made by the sheet metal fabrication route. This includes integrally machined wing cover
skin stringers, machined spars (with web crack stoppers), and ribs, thus enabling a reduction in
fastener weight, less scope for fatigue cracking propagating from fastener holes, reduced parts
count and assembly costs. Also joining high speed machined components can be achieved with
bath tub joints or integral end tabs without the need for separate cleats and additional fasteners.
Other weight savings have been gained from the application of titanium alloy in place of steels for
highly loaded or high temperature components produced as near net shape forgings, or even in the
case of Super Plastically Formed titanium alloy structures employed as lower wing access port
panel covers, replacing the formally sheet fabricated covers. Titanium is also more compatible than
aluminum when used with composites in that it is not susceptible to galvanic corrosion and has a
compatible coefficient of thermal expansion. Also the adoption of Aluminium Lithium alloys in such
applications as wing ribs with a density saving of 5% over conventional aluminium alloy structures.
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Design of Machined and sheet metallic components for design studies.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 62(a) Example of 3 axis machining:-
3 Axis Machining:-
During machining the cutter can move simultaneously
along the X,Y & Z axes. The tool axis orientation is fixed
during machining. Usually used for simple geometries
where missed material is not a major issue.
(This example shows the spiral milling of a shallow
pocket feature on a compound surface).
Figure 62(b) Example of 5 axis machining:
5 Axis Machining:-
During machining the cutter can move along the X, Y &
Z axes and rotate around e.g. the X & Y axes
(designated A & B axes motion) during the machining
cycle. This capability enables the Fanning and Tilting of
the tool during machining for complex deep pockets
where excess material is an issue.
Fig 62 (a/b):- Machining Methods for Metallics applied in the design studies.
X+
Z+
Y+
A
B
Figure 62(b)
X+
Z+
Y+
Figure 62(a)
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Design for Manufacture:-
To machine an External Flange surface produced as a
result of splitting the model with a „complex‟ surface is both
time consuming and costly.
Therefore to aid manufacturing, the „complex‟ surface can
be replaced by a „ruled‟ surface provided the Chord Height
Error (CHE) is within the values specified in Design
Standards. (see Figure 63)
Where the CHE value exceeds the specified maximum, the
flange is produced by splitting the model with a „faceted‟
surface. (see Figure 64).
A bespoke „Flange‟ application will be available in the near
future to automate the creation of the „Faceted Ruled
Surface‟. As this was not available at the time of writing, the
exercise accompanying the course requires manual
generation of this geometry
External Flanges produced by complex surfaces are
permissible, but should only be used in extreme cases and
in agreement with manufacturing due excessive machining
costs
Fig 63/64:- Machined Metallics:- Chord Height Error applied in the design studies.
Figure 63 Figure 64
CHE
Preferred Non-Preferred
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Design for Manufacture:-
In Figure 65 the area shaded in Black indicates the 5
Axis Landing, and is the remaining material following
machining of the internal face of the closed angle
flange, and represents the difference between the „as
designed‟ and „as manufactured‟ part.
In such cases, it is a mandatory requirement for
allowances to be made for the loss of fastener seating
area.
The remaining material can be further reduced by
additional machining.
The area shown in Black in Figure 66 represents the
preferred condition of 5 axis landings following
machining.
Figure 65
Figure 66 Preferred
Fig 65/66:- Machined Metallics :- 5 axis landings applied in the design studies.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 67:- My Catia V5.20 machined Frame X_700 FWD face, from OML surfaces.
111
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
112
Figure 68:- My Catia V5.20 machined Frame X_700 AFT face, from OML surfaces.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
113
Figure 69:- Example of my Catia V5.20 FD&T application to Frame X_700.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
114
Figure 70:- Example of my Catia V5.20 metallic design of complex components.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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Generative Sheet Metal is typically used to design parts which are typically manufactured
using „V‟ benders or press tooling. This workbench cannot produce features such as Flanges
which reference surface geometry, or to create „Joggle‟ features.
Aerospace Sheet Metal is typically used to design parts which are typically manufactured
via the „Hydroforming‟ process. This workbench can produce features such as Flanges which
reference surface geometry, and to create „Joggle‟ features.
Functionality Overlap Certain functions are common to both workbenches (sometimes
with limitations), and others are workbench specific. The following table outlines these
functions:
Generative Sheet Metal only icons
Aerospace Sheet Metal only icons
Common Icons
Limited functionality compared to
Generative Sheet Metal workbench
Chart 10:- Design of sheet metallic components for capability maintenance.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Chart 11:-Catia V5.R20 „New Part‟ Sheet metal process overview.
Select Generative Sheet Metal Design from Shareable Products tab in Tools / Options / General
Create New file
Enter Generative Sheet Metal Design workbench
Set Sheet Metal Parameters
Create Wall
Create Features
Check Flattened Component
Create Block and Heel Lines / Curves
Save CATPart
This was a specific BAE Sheet Metal methodology.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 71:- Example of my Catia V5.R20 Aerospace sheet metal frame design.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
118
Figure 72:- Example of my Catia V5.R20 Generative sheet metal design work.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 73:- Example of my Catia V5.R20 Generative sheet metal design work.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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Open Model
Analyse Surface
Create Surface
Create Wireframe Geometry
Save Model
Condition Model
Production
Standard?
YES
NO Smooth Surface
Final Checks
Cutting Planes
Distance Analysis
Porcupine Curvature
Connect Checker
Local Smoothing
Smooth Discrepancies
View Modes
Global Smoothing
No Hyperlink
Hyperlink to Task
KEY
Global
deformed
surface ?
Split YES
NO
Chart 12:- Surface process workflow used to create my project surfaces.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
121
Figure 74:- Project Wing torsion box datum surface model.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
122
Figure 75:- Project Wing carry through box datum surface model.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
123
Figure 76:- ICEM curvature analysis applied to my wing project surfaces.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Create new drawing
Create Project Specific Drawing Border
Filtering Data for Assembly Views
Instantiate Catalogue Details if required
Annotate Views if required
Save CATDrawing
View Creation
View Modification Options
Assembly View Content Modification
Create Drawing Comments
= Hyperlinks
Manual Pre-selection
Scenes
From Scenes
Spatial Query
Lock the Views
Overload Properties
Modify Links
Local Axis System
No Hyperlink
Hyperlink to Task
KEY
124
Chart 13:- Catia V5.R20 New Drawing Overview / Process Outline.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Figure 77:- Example of my Catia V5.20 frame X-700 metallic machined part.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
126
Figure 78:- Example of my Catia V5.20 metallic machined assembly.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
127
Figure 79:- Example of my Catia V5.20 metallic sheet metal part.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
N
Y
Is a Key
Diagram
available?
Does
Production
Assembly
exist?
Does Data
already
exist?
Is Reference
Geometry modelled
in local axis?
Chart 14:- Catia V5.R20, Adding To / Creating Data in a Production Assembly.
Start
Y
N
Verify Position of Data
N
Open Production Assembly Create Production Assembly
Insert Existing Data Add New Data
Y Snap data to Key Diagram
Position as required
N
Y
No Hyperlink
Hyperlink to Task
KEY
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
The BAE Systems methodology of Product Assembly creation.
Is also referred to as the „Vehicle Assembly‟
In CATIA V5 terms, it is the CATProduct holding all
the CATIA data relevant to the design of this
„vehicle‟, in effect, it is the „virtual aircraft‟ - the
DMU
Within this structure, key parts are located with
respect to a Key Datum product which was also
used to position the „reference geometry‟
To ensure engineers working on the project have
access to the correct „reference data‟, the content
of the product structure is organised such that the
data is held within „master models‟ located in the
upper region of the tree structure in a component
node named „REF_REFERENCE_GEOMETRY‟
Designers take the required reference geometry
from the „master model(s)‟ into their own after
inserting and positioning it correctly within the A\C
environment
This „master geometries‟ methodology will be
employed throughout the FATA project.
Production (or Vehicle) Assembly Reference geometry „container‟
„Reference geometry‟
assemblies by „design
discipline‟
„Design assemblies‟
by „design discipline‟
Std. Parts „container‟
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Chart 15:- Catia V5. R20 Assembly Positioning Options.
Various positioning options are available, the majority of which were covered during the Fundamentals course
The functions illustrated are available in the Assembly Design and Digital Mock-Up (DMU) Navigator
workbenches
These functions illustrated have been used by myself at BAE Systems and will be employed in the FATA project.
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
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Figure 80:- Example of my Catia V5.20 simple robot assembly in DMU.
AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
Chart 16:- Creating a Production Assembly with Reference Geometry.
Create New Production Assembly
Create a New Reference Component and Fix
Check for latest and Insert Key
Diagram into Reference
Component and Fix
Check for latest and Insert
Reference Geometry into
Reference Component
Snap data to Key Diagram and Fix
Is the Reference Geometry
modelled in local axis?
Y
N
N
Y
Fix Geometry
Is a Key Diagram available?
Insert Reference Geometry into
Reference Component
Position as required
Fix Geometry
No Hyperlink
Hyperlink to Task
KEY
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AIAA Mr. Geoffrey Allen Wardle MSc. MSc. C.Eng.
My future design career aims are within advanced aircraft design.
133
Figure 81(a):- Design and development of aircraft composite
and metallic major airframe structures to JAR-25.571
Figure 81(b):- Design and
development of advanced
aero engine structures to
JAR-E510/520