Recent Enhancements for Composite Design Optimization

Recent Enhancements for

Composite Design Optimization

Ming Zhou, Raphael Fleury

Altair Engineering, Irvine, California

Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Agenda

1. Brief Overview of Composite Optimization Process

2. Ply Drop-off Constraints and Other Enhancements

3. Application Examples

3. Conclusion


Composite Optimization Process

Automation

Patch Interpretation

Tailoring?

Free Sizing!

Phase 1

Number of Plies?

Ply Bundle Sizing!

Phase 2

Laminate Stacking?

Optimized Stacking

Sequence!

Phase 3

Rule based

ply shuffling

45 -45 0 0 0

45 -45 45 90

90 -45 45 -45 0 0

-45 90 45

(a) Ply Level (b) Superply Level

45 -45 0 0 0

45 -45 45 90

90 -45 45 -45 0 0

-45 90 45


Discrete Ply Thickness

Automation


Composite Box Beam


Composite Optimization Process

Phase III - Detail: Stacking Sequence Optimization

• Meet ply book rules

• All behavior constraints

• Stacking manufacturing constraints

45 -45 0 0 0

45 -45 45 90

90 -45 45 -45 0 0

-45 90 45


45 -45 0 0 0

45 -45 45 90

90 -45 45 -45 0 0

-45 90 45



T_45Ply

T_ - 45Ply

Balance_45Ply, T_45Ply = T_ - 45Ply

Composite Manufacturing Constraints

Min/Max Total Laminate Thickness Min/Max Individual Ply Thickness (e.g., Min/Max 0-Deg Thickness…) Min/Max Individual Ply Angle Percentage (e.g, Ply90 %...) Balanced Ply Angles (i.e. Balance +/- 45’s) Constant Individual Ply Thickness Ply Draping Accommodation Zone based Pattern Grouping Ply Drop-Off Constraints Can be applied to Composite Free-Size and Composite Size Optimization

T = Ply4 (nom) 45

PCOMP

T = Ply3 (nom) 90

T = Ply2 (nom) -45

T = Ply1 (nom) 0

T_Laminate Min/Max T_0Ply Min/Max = Sum(T_0Ply)

T = Ply1 (nom) 0

T = Ply2 (nom) -45

T = Ply3 (nom) 90

T = Ply4 (nom) 45

T_Laminate

T_90Ply (1)

Ply90% =

Sum(T_90Ply)/T_Laminate

T_90Ply (2)

T_0Ply Constant


Composite – Concept Design

Manufacturing Constraints:


Composite – Concept Design


),( | | :rate drop Ply kjdistikij xx


Free Size Optimization – Manufacturing Constraints

• Ply Drop-Off Constraints

• Reduce stress concentrations leading to failure through delamination

• Thickness drop-off for free-sizing

• Actual drop-off for sizing

• Directional drop-off control

• Constraints can be defined based on the slope or thickness

• Available in composite free sizing optimization (element based)

• Available in composite sizing optimization (property/ply based)


Drop – Off Constraints: Plate Example



• Visualization of Manufacturing Constraints in H3D

No Drop-Off

Constraint Ply Thickness

Ply Thickness

1% Drop-Off

Constraint

Ply Drop-Off

Contour

Max =1%

Ply Drop-Off

Contour

Max =20%

Cantilever

Plate


Free Size Optimization – Usability Enhancements

• Automatic Offset Updating (ZOFFS and Z0)

• Improved process for working with and optimizing models where the mesh is at

TOP or BOTTOM surface of physical thickness

• Works with shells and composites

• Works for free sizing and sizing optimization

• Automatic Generation of Ply Bundle Sizing Model (OUTPUT,FSTOSZ)

• Rewritten using a pure ply based approach

• Advanced algorithm to capture thickness variation is now available for 2, 4 and 8

ply bundles

• Multiple ply bundle generation methods (ADVFREE, ADVMAN, SIMFREE,

SIMMAN)

• IGNORE option for plies with very low thicknesses


Free Size Optimization – Usability Enhancements

• Designable Core Layer

• Core can also be free-sized

• Used with SMCORE (smeared core) laminate definition

• Optionally, can be set as non-design

• Support for Mixed Ply Structures

• Different ply layups for different properties



• Constraints can be defined BYPLY and BYSET (set of plies) in addition

to BYANG (by orientation)

• Comprehensive solution allowing various options to apply manufacturing

constraints

• Constraints by material can be applied using BYSET option

• Constraints can be defined locally

• Account for regions requiring reinforcements such as bolt or mounting locations

• Different manufacturing requirements for different sections of the design

• EXCLUDE option to exclude CORE or CONST (plies defined in the

CONSTant constraint) from certain manufacturing constraints



• Consistent syntax on the DSIZE (free sizing) and DCOMP (ply bundle

sizing) cards

• Manufacturing constraints are automatically carried over from free sizing to sizing

• Preserves continuity of manufacturing constraints across the optimization process


Bombardier Composites Optimization

Optimization of Composites – Zone-Based Pattern Grouping and DRESP3

Successful integration/application of

composite optimization process in live

aerospace design environment


Composite Wing

Composite skins with 0, +45/-45, 90 plies


max. ply thickness ≤ 10 mm

+45/-45 plies linked

8 mm ≤ total thickness ≤ 32 mm

min. ply percentage ≥ 10%

Minimize Mass

Subject to:

Tip displacement constraints

(Bounds different for 10 load cases)

Phase I - Concept: Free-Size


PLY DROP-OFF – WING EXAMPLE

NO DROP-OFF

CONSTRAINT

PLY THICKNESS

PLY THICKNESS

WITH 1% DROP-OFF

CONSTRAINT


Ply sequence optimisation

• Utilities created to generate solid visualisation of plies

• Thickness scale factor applied (x5)

• Element & ply Z offsets included

• Top cover:


OSSmooth Enhancements – Ply Shape Interpretation

• Benefits

• FE based plies need to be manually interpreted

• OSSmooth interprets ply shapes

• Ply boundary smoothing

• Treatment for small ply patch regions – keep or discard

• Disconnected patches can be created as separate ply entities

• OptiStruct ply bundle sizing deck is generated with updated data

• Streamlined overall composite optimization process


elimination of small regions

smoothing on ply shapes

Example – ply shape interpretation


SmallRegion = 0.001 (by area ratio)

SmallRegion = 0.003 (by area ratio)

original ply shape

Example – ply shape interpretation


Conclusions

• Comprehensive Composite Optimization Process

• Three-Phase optimization process – from concept to Ply-Book details

• Manufacturing constraints through out the process

• Ply-Drop constraints

• Ply shape smoothing tool

• Quick adoption by aero, race car, yacht industries

• Ongoing R&D

• Stress/strain/failure index constraints for Free-Size phase

Recent Enhancements for Composite Design Optimization

Technology

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