Structural Steelwork

8/12/2019 Structural Steelwork

1/130

Structural Eurocodes

W.M.C. McKenzie B.Sc., Ph.D., C.Phys., M.Inst.P., C.Eng.SOEBE, Edinburgh Napier University

The Design of Structural Steelwork

to EN 1993 (EC3)
http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


2/130

copyright protected

This evenings presentation

1. Introduction to, and development of, the Eurocodes

2. Design of structural steelwork to EN 1993-1 (EC3)

3. Sources of information

Dr. W.M.C. McKenzie2


3/130

copyright protected

The Construction Products Directive (CPD) Council

Directive 89/106/EEC, is one of over 20 New Approach

Directives whose aim is to breakdown artificial barriers

to trade throughout the EU and is intended for products

placed on the market.

(EEC initiated the programme in 1975.)

The Construction Products Directive



4/130

copyright protected

Essential Requirements to be satisfied byproducts suitable for construction:


1. Mechanical resistance and stability.

2. Safety in case of fire.

3. Hygiene, health and the environment.

4. Safety in use.

5. Protection against noise.

6. Energy, economy and heat retention.

Applicable to the Eurocodes.


5/130

copyright protected

CE marking is mandatory for products covered by a Directive

and allows them to circulate freely within the European

Economic Area.

It follows the successful approval of a product and symbolises

the conformity of the product with the Directive.

The use of Eurocodes raises a presumption of conformity with

Essential Requirement 1, and parts of Essential Requirements 2

and 4 of the Construction Products Directive.

CE Marking:



6/130

copyright protected

A set of European Standards (e.g. EN 1993-1-1) for the design of

buildings and other civil engineering works and construction

products, produced by the Comit Europen de Normalisation

(CEN)the European Committee for Standardisation.

(The programme to establish ENs began in 1989).

They embody National experience and research output, together

with the expertise of CEN Technical Committee 250

(CEN/TC250)and other international technical organisations.

What are Eurocodes?



7/130 copyright protected

The Eurocode Suite


EN 1990 Eurocode Basis of Structural Design

EN 1991 Eurocode 1 Actions on Structures

EN 1992 Eurocode 2 Design of Concrete Structures

EN 1993 Eurocode 3 Design of Steel Structures

EN 1994 Eurocode 4 Design of Composite Steel & Concrete Structures

EN 1995 Eurocode 5 Design of Timber Structures

EN 1996 Eurocode 6 Design of Masonry Structures

EN 1997 Eurocode 7 Geotechnical Design

EN 1998 Eurocode 8 Design of Structures for Earthquake Resistance

EN 1999 Eurocode 9 Design of Aluminium Structures

(Note:an additional code is currently being developed for the use

of structural glass.)

Table 1


8/130 copyright protected Dr. W.M.C. McKenzie8

EN 1991 Parts 1 to 4:

Eurocode 1

Part 2: Traffic Load

Part 1-1: Densities/self-

weights & Imposed loads

Part 1-3: Snow

Part 1-2: Fire

Part 1-5: Thermal Actions

Part 1-6: Actions during

execution

Part 1-7: Accidental Actions

Part 1-4: Wind Actions

Part 3: Cranes & Machinery

Part 4: Silos & Tanks

National Annexes

Figure 1



The Links Between the Eurocodes


EN 1990

Head Eurocode

Structural safety, serviceability,durability and robustness

EN 1991 Actions on structures

EN 1998EN 1997 Geotechnical and seismic design

Design and detailing

EN 1992 EN 1993 EN 1994

EN 1995 EN 1996 EN 1999

Figure 2



Why Use the Eurocodes?


They comprise a complete set of design standardsthat cover

all principal construction materials and all major fields of

structural engineering.

They are the most advanced codes of practice in the world.

they are flexible, offering the possibility for each country to

choose levels of safety through Nationally Determined

Parameters (NDPs).

They provide design methods whose development has been

fully transparent, and promote innovation in structural

design.



Benefits and Opportunities


They lead to more uniform levels of safety in construction

throughout Europe.

They provide common design criteria and methodsto fulfil

the specified requirements for mechanical resistance, stability

and resistance to fire, including aspects of durability and

economy.

They provide a common understanding between owners,

operators and users, designers, contractors and manufacturers.



Benefits and Opportunities (cont.)


They provide a common and transparent basis for fair

competition in the construction market.

They facilitate the exchangeof construction services.

They allow the preparation of common design

aids/software and a common basis for research and

development.

They increase the competitiveness of the European civil

engineering firms, contractors, designers and product

manufacturers in their world-wide activities.



Examples of Structures Designed Using the Draft(ENV) and Final (EN) versions of Eurocodes

Roof of the Lige railway station, Belgium(ENV 1991- loading & ENV 1993 - steelwork)


Bridge over Wadi Dib, Algeria(EN 1998earthquake design)

Roccaprebalza Viaduct, Italy

(EN 1992, EN 1993 & EN 1994) S. Gabriel and S. Rafael Towers, Portugal

(EN 1994, - composite construction)Figure 3


14/130

copyright protected

CEN committee structure

e.g. The sub-committee for Eurocode 3 for

the design of steel structures:CEN/TC 250/SC 3


CEN

SC 0 SC 1 SC 2 SC ....SC 3

TC 250 TC ...... TC ......TC ......

Figure 4


15/130

copyright protected

The implementation of an EN Eurocode Part by National

Authorities and National Standards Bodies after is made

available by CEN [i.e. Date of Availability (DAV)] has

three phases:

1. Translation period,

2. National Calibration period,

3. Coexistence period.

15

National Implementation of Eurocode Part

Dr. W.M.C. McKenzie


16/130

copyright protected16

National Calibration Period: maximum 2 years

Dr. W.M.C. McKenzie

1. The Member States fix the Nationally Determined Parameters

(NDPs).

2. At the end of the period, the national version of the Eurocode Part

with the National Annex, should be published by the National

Standards Body.

3. The Member States should adapt the National Provisions so that

the Eurocode Part can be used on their territory.


17/130


Coexistence Period: maximum 3 years

Dr. W.M.C. McKenzie

1. During this period the Eurocode Parts can be used in parallel with

the existing code system.

2. The coexistence period of a Eurocode Packagewill last up to a

maximum time of three years after the national publication of the

last Part of a Package.

3. Member States should ensure that all the Parts of a related Package

can be used without ambiguity.

4. At the end of the coexistence period all conflicting National

Standards should be withdrawn.


18/130


Parts

Dr. W.M.C. McKenzie

All of the EN Eurocodes relating to materials have a Part 1-1 which

covers the design of buildings and other civil engineering structures and a

Part 1-2for fire design. The codes for concrete, steel, composite steel and

concrete, and timber structures and earthquake resistance have a Part 2

covering design of bridges. These Parts 2 should be used in combination

with the appropriate general Parts (Parts 1).

Part 1-1

General

rules andrules for

buildings

Part 1-2

Structural

Fire Design

Part 2

Bridges

Part 3...

.............

Figure 5


19/130


20/130

copyright protected20Dr. W.M.C. McKenzie

The EN Eurocode Parts have been grouped into Packages, each

of which must be published before the implementation of that set

of EN Eurocodes may begin. EN 1990, EN 1991, EN 1997 and

EN 1998 are material independent and are therefore included in

each package.

Packages


21/130


Packages (cont.)

A Package is a group of EN Eurocode Parts that are needed for a

particular design (e.g. for a building, a bridge, a silo, a tank or a

pipeline).

The purpose of defining packages, by grouping Parts of EN

Eurocodes, is to enable a common Date of Withdrawal (DoW)

for all of the relevant National Standards that are needed for a

particular design.


22/130


Packages (cont.)

When a National standard has a wider scope than the conflicting

EN Eurocode Package, only that part of the National standard

whose scope is covered by the Package has to be withdrawn.

When more than one package of EN Eurocodes is likely to be

needed for the design of works, the dates of withdrawal of the

related Packages can be synchronized.


23/130

copyright protectedDr. W.M.C. McKenzie

23

3/1: Design of steel building and civil engineering structures

(excluding bridges, silos, tanks and pipelines, steel piling,

crane supporting structures, and towers and masts).

3/2: Design of steel bridges.

3/3: Design of steel silos, tanks and pipelines.

3/4: Design of steel piling.

3/5: Design of steel crane-supporting structure

Eurocode 3 Packages: Steel Structures


24/130


Package 2.1Concrete Building and Civil Engineering Structures

Courtesy H. GulvanessianFigure 6


25/130

copyright protected

Eurocodes Timeline:Duties of National Authorities & Standards Bodies

25

National Implementation of Eurocode Part

Maximum 2 years Maximum 3 years

Date of Availability

(DAV)

Publication of Part and

National Annex

Fixing Nationally

Determined

Parameters (NDPs)

Adaptation of NationalProvisions to allow use

of Eurocodes

Translation toNational Language

Final Adaptation ofNational Provisions

Withdrawal of all conflicting

National Standards by March 2010

Note: Publication of the Eurocodes

was completed in May 2007

Dr. W.M.C. McKenzie

Maximum period of 5 years

Figure 7


26/130

copyright protected

54 complete4 awaited

26

UK - Eurocode Parts and Annexes Published

Dr. W.M.C. McKenzie

58 Parts in total

Figure 8


27/130

copyright protected

Are the EN Eurocodes Mandatory?


Under the Public Procurement Directive,

it is mandatory that Member States accept designs to the

EN Eurocodes. The EN Eurocodes will become the standard

technical specification for all public works contracts. If

proposing an alternative design one must demonstrate that

istechnical ly equivalentto an EN Eurocode solution.


28/130

copyright protected

Are the EN Eurocodes Mandatory? (cont.)


Technical equivalence

A contracting authority "cannot reject a tender on the

grounds that the products and services tendered for do not

comply with the specifications to which it has referred,

once the tenderer proves in his tender to the satisfaction of

the contracting authority, by whatever appropriate means,

that the solutions which he proposes satisfy in an

equivalent manner the requirements defined by the

technical specifications."

Directive 2004/18/EC of the European Parliament and of the Council of 31 March 2004.


29/130

copyright protected



Technical equivalence may be admissible provided it

is shown that the alternative rules accord with the

relevant Principles of the EN Eurocodes and are at

least equivalentwith regard to mechanical resistance,

stability, fire resistance and durability which would be

expected using the EN Eurocodes.


30/130

copyright protected



As the National Standardisation Bodies are not expected to

maintain the withdrawn National Standards in practice,

there will be little option but to use the EN Eurocodes. It is

extremely likely that pressures from international clients

and contractors, as well as other stakeholders like the

insurance industry, will lead to their more rapid application

for private construction.


31/130

copyright protected



For the purpose of products obtaining CE

marking under the Construction Products Directive,

Member States should refer to the EN Eurocodes in

their national provisions on structural construction

products, thus making them mandatory for this

purpose.


32/130


32

National Title Page National Foreword EN Title Page

EN Text EN Annexes National AnnexFigure 9


33/130

copyright protected

EN Annexes are either:

1. Normative containing information which must be

followed.

or

2. Informative containing supplementary information

which maybe followed.

EN Annexes


EN Annexes: e g in EN 1993-1-1 & EN 1993-1-5


34/130

copyright protected

EN Annexes: e.g. in EN 1993-1-1 & EN 1993-1-5structural steelwork


Figure 10


35/130

copyright protected

National Annexes

A National Annex (NA) is the linkbetween a Eurocode and

the National Standards for a Member State.

It contains rules and parameters to ensure safety remains a

National, and not a European, responsibility.

The foreword of each Eurocode Part lists paragraphs in which

national choice is allowed. However, the National Annex has

limited overriding authority to the Eurocode.



36/130

copyright protected

National Annexes (cont.)

ANational Annex cannot change or modify the

content of the EN Eurocode text in any way other than

where it indicates that national choices may be made by

means of Nationally Determined Parameters.


Guidance Paper L(see http://eurocodes.jrc.ec.europa.eu )


37/130

copyright protected

National Annexes (cont.)

The National Annex reflects specific needs of individual countries in

the Eurocode.

A National Annex exists for each Eurocode Part.

National Annexes provide:

Nationally Determined Parameters (NDPs),

Country specific data (e.g. snow maps, wind maps etc.),

Procedures to be used where a choice is offered,

Guidance on the informative annexes,

Reference to non-contradictory, complementary information,

(NCCI)



38/130

copyright protected

Nationally Determined Parameters

EN Eurocodes recognise the responsibility of regulatory

authorities in each Member State and have safeguarded their

right to determine values related to regulatory safety matters

at a national level where these continue to vary from State to

State.

EN Eurocodes provide for National Choices, full sets of

recommended values, classes, symbols and alternative

methods to be used as Nationally Determined Parameters

(NDPs).



39/130

copyright protected

Nationally Determined Parameters (cont.)

When the EN Eurocodes are used for the design of

construction works, or parts thereof, the NDPs of the

Member State on whose territory the works are located shall

be applied, e.g.


Characteristic snow load on the ground:

sk

EN 1991-1-3:Annex C

Ground snow load map

UK National AnnexGround snow load map

Figure 11

i i ( )


40/130

copyright protected

Nationally Determined Parameters (cont.)Extract from

UK National Annex to EN 1993-1-1:

Design of steel structures

Part 1-1: General rules and rules for

buildings


Note:

A National Standardisation Board is not

permitted to publish a National version of a

Eurocode with the NDPs from the National

Annex incorporated in to the EN text.

(Users may find it useful to mark up their

own copies of the EN from the NA.)

Figure 12


41/130

copyright protected


Database of Nationally Determined Parameters

A database with the Nationally Determined Parameters adopted

in the EU and The European Free Trade Association (EFTA)

countries implementing the EN Eurocodes will constitute the

basis for the analysis of the NDPs and for the definition of

strategies tending to achieve further convergence and

consequently aiming at facilitating the achievement of the

European Single Market for construction works and structural

construction products.


Nationally Determined Parameters (cont )


42/130

copyright protected



Extract from the database of Nationally Determined Parameters

Progress of uploading of

NDPs (October 2009)

Uploaded

NDPs

Not registered

Registered

25%53%

22%

Figure 13

Last updated: 4th. September 2009

Source: http://eurocodes.jrc.ec.europa.eu


43/130

copyright protected

Non-contradictory Complimentary Information

Most existing national codes include some provisions that

are not in the Eurocodes. Provided that the material is

consistent with the Eurocodes, it can be advisory or a

requirement in that country. It is known as "non

contradictory complimentary information(NCCI).


Non contradictory Complimentary Information (cont )


44/130

copyright protected

Non-contradictory Complimentary Information (cont.)


Figure 14

Non contradictory Complimentary Information (cont )


45/130

copyright protected

Non-contradictory Complimentary Information (cont.)


Figure 15

Principles and Application R les


46/130

copyright protected

Principles and Application Rules

The Clauses given in the Eurocodes are either:

Principles or Application Rules

The Principles are general statements, definitions,

requirements or analytical models for which there is no

alternative permitted. They are identified by (P) after the

clause number.

The Application Rulesare generally recognised rules whichare recommended methodsof achieving the Principles.


Ultimate Limit States (cont)


47/130

copyright protected

Ultimate Limit States (cont)

The Ultimate Limit States are considered in four categories in

the Eurocode. They are:

(i) EQU: relating to the static equilibrium of a structure or

any part of it which is considered as a rigid body,

(ii) STR: relating to internal failure or excessive deformation

of a structure or structural member,

(iii) GEO: relating to failure or excessive deformation of the

ground,

(iv) FAT: relating to fatigue failure of structural members.



48/130

copyright protected

Differences From British Standards

BSs have no equivalent to Eurocode EN1990:

(establishes for all structural Eurocodes, the Principles and

Requirements for safety, serviceability and durability.

Traditionally in BSs this has been replicated in each code

separately.)

The structure of the Eurocodes is phenomenon basedrather

than member basedas in the British Standards.



49/130

copyright protected

Differences From British Standards (cont.)

EN 1991 uses different load combinations from the BSs:

Three different types of combination are given in the Eurocode.

They are:

combinations of actions for persistent or transient design

situations (fundamental combinations),

combinations of actions for accidental design situations,

combinations of actions for seismic design situations.



50/130

copyright protected


The Eurocodes do not provide standard /derived formulae

these are considered to be textbook material; e.g. in steel

design, the formula to determine the elastic critical moment

(Mcr) required to evaluate the lateral torsional bucklingresistance is not given, (see NCCIs from the access steel

website or other sources).

The unit of stress is the MPa (in UK refer to N/mm2)

although not consistently so.


Diff F B iti h St d d ( t )


51/130

copyright protected


The axes are different from that traditionally used in the UK:


z

z

x

x

y

y

y

z

z

x

x

y

Eurocode System UK System

There are implications when considering instability andslenderness calculations!

Figure 16


52/130

iff i i S ( )


53/130

copyright protected


Beware of inconsistent symbol definitions, e.g. EN 1993:1-1


Figure 17

Differences From British Standards (cont )


54/130

copyright protected

Standard ISO practice has been adopted in representing

a decimal point by a comma, i.e. 5,3 5.3. In the UK, to

avoid confusion, engineers should avoid using a comma

to indicate thousands (as is common practice) if they do

not adopt Standard ISO practice, i.e.

3534.1 3.5341 1033534,1 3,5341 103 (Not 3,534.1)



T i l


55/130

copyright protected Dr. W.M.C. McKenzie55

Terminology

Actions:

Permanent/variable loads, imposed displacements, thermalstrains etc.

Effects:

Internal axial forces, shear forces, bending moments etc.

Resistance:Capacity of structural elements to resist design effects.

Verification:

Checking the suitability of structural sections.

Execution:

Fabrication, erection etc. of construction.

Symbols


56/130


Symbols

Design value of an effect: subscript (Ed)

e.g. MEd design bending moment.

Design value of the resistance: subscript (Rd)

e.g. MRd design resistance for bending moment.

Elastic section property: subscript (el)

e.g. Wel elastic section modulus.

Plastic section property: subscript (pl)

e.g. Wpl plastic section modulus.

Effective section property: subscript (eff)

e.g. Aeff elastic section modulus.

Acronyms


57/130

copyright protected

Acronyms

CEN Comit Europen de Normalisation.

CPD Construction Products Directive.

NA National Annex.

NDP Nationally Determined Parameter.

NCCI Non-contradictory Complimentary Information.

DAV Day of Availability.

ENV Draft Version of a Code Part for comment. (DD ENV)

EN EuroNorm: Final Version of a Code.

DoW Date of Withdrawal.

http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


58/130


Design Situationsand

Load Combinations to EN 1990


59/130


Design Situations (EN 1990)

Persistent:e.g. normal use of a structure.

Transient:

e.g. temporary situations, e.g. execution.

Accidental:

e.g. exceptional events, e.g. fire, impact explosion.

Seismic:e.g. effects of earthquake loading .

Ultimate Limit State Combinations (EN 1990)


60/130



For persistent and transient design situations:

G,j k,j Q,1 k,1 Q,j 0,i k,i1 1 Equation (6.10)

pj iG P Q Q

G,j k,j Q,1 0,1 k,1 Q,j 0,i k,i

1 1

Equation (6.10a)pj i

G P Q Q

For Equilibrium limit states (EQU) only Equation (6.10) should be used. For

Strength limit states (STR) and Geotechnic limit states (GEO) either

Equation (6.10) or the less favourable of (Equation (6.10a) and (6.10b) may

be used.

j G,j k,j Q,1 k,1 Q,j 0,i k,i

1 1

Equation (6.10b)pj i

G P Q Q

leading variable accompanying variables
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


61/130



For accidental design situations:

where1,1

Qk,1

or2,1

Qk,1

is dependent on the accidental situation e.g.

impact, fire etc.

For seismic design situations:

k,j 1,1 2,1 k,1 0,i k,i1 1

or Equation (6.11b)dj i

G P A Q Q

k,j 0,i k,i

1 1

Equation (6.12b)Edj i

G P A Q

Serviceability Limit State Combinations (EN 1990)
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


62/130



Characteristic combinations:

This should be used when considering an irreversible serviceability

limit state, functioning of a structure, damage to finishes or non-

structural elements e.g. partition walls, caused by excessive deflection.

Frequent combinations:

This should be used when considering reversible limit states, e.g. non-permanent displacement of a floor supporting a machine that is

sensitive to vertical alignment, avoiding ponding of water etc.

Quasi-permanent combinations:

This should be used when considering reversible limit states or long-

term effects, e.g. when considering appearance, creep etc.



63/130



For characteristic combinations:

For frequent combinations:

For quasi-permanent combinations:

k,j k,1 0,i k,i1 1

Equation (6.14b)pj i

G P Q Q

k,j 1,1 k,1 2,i k,i

1 1 Equation (6.15b)p

j iG P Q Q

k,j 2,i k,i

1 1

Equation (6.16b)j i

G P Q

UK N.A. to EN 1993 indicates that only variable loads should be considered.

Design of structural steelwork to EN 1993
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


64/130


Design of structural steelwork to EN 1993

BS 4491 Part: 120 A5 pages / 77 A4 pages

(1969metric version, original version 1932)

BS 59509 Parts: 569 A4 pages

(1990)

EN 199320 Parts: 1291 A4 pages

(March 2010conflicting codes withdrawn)

Design of Structural Steelwork to EN 1993-1


65/130


Design of Structural Steelwork to EN 1993 1

EN 1993-1 comprises twelve parts. In most cases the following

parts will be required:

EN 1993-1-1:General rules and rules for buildings.

EN 1993-1-2:Structural fire design.

EN 1993-1-3:Cold formed thin gauge members and sheeting.

EN 1993-1-5:Plated structural elements.

EN 1993-1-8:Design of joints.

EN 1993-1-10: Selection of steel for fracture toughness and

through-thickness properties.

Material Properties: yield strength (fy) and ultimate


66/130


Material Properties: yield strength (fy) and ultimatestrength (fu)

Values for the yield strength and the ultimate strength of steel are given in

Table 3.1 of EN1993-1-1:2005 (E) for a range of steel grades and

thicknesses.

Figure 18

non-alloy

structural steels

?

Material Properties: yield strength (fy) and ultimate


67/130


Material Properties: yield strength (fy) and ultimatestrength (fu)

The UK NA indicates that the values of yield strength fyand the ultimate

strengthfushould be obtained from the product standard e.g. EN 10025-2.

Figure 19

= fy = fu

Material Properties: comparison of EN 1993-1-1 and


68/130


p p N 3EN 10025-2

A comparison of the EN1993-1-1 and the EN10025-2 values is given in

Table 2 below.

Table 2

Steel grade

EN 1993-1-1 EN 10025-2

Thickness

(mm) fy (MPa)

Thickness

(mm) fy (MPa)

S275 t 40 275 t 16 275

16


69/130


ate a ope t es: ou g s odu us, s ea odu us,Poissons ratio and the coefficient of thermal expansion

Values of the standard elastic material coefficients is given in Clause 3.2.6

as follows:

Modulus of elasticityE= 210 103 MPa

Shear Modulus G 81 103 MPa

PoissonsRatio = 0,3

Coefficient of thermal expansion= 12 10-6/K (forT100C)

(Note:for composite concrete-steel construction = 1010-6/K)

Partial Factors for Material Strength (Mi)


70/130


g ( Mi)

The material partial safety factors are dependent on the resistance being

checked as follows:

M0 is used when verifying the resistance of cross-sections of any class,M1 is used when verifying the resistance of members to instability assessed

by member checks,

M2 is used when verifying the resistance of tension members to fracture.The values given in the UK N.A. are:

M0 = 1,0; M1 = 1,0; M2 = 1,1Values to be used for the resistance of joints are given in EN1993-1-8:

M0toM7depending on the element being considered, i.e. bolt, weld, pin etc.

Conventions for Member Axes


71/130


Figure 20

z-z

y-y

x-x

Ultimate Limit States: Elastic Verification for Resistance


72/130


Verification may be carried out using the von Mises yield criterion where

the interaction of local stresses are limited to thefy/M0as follows:

where:

x,Edis the design value of the local longitudinal stress,

z,Edis the design value of the local transverse stress,

Ed is the design value of the local shear stress.

This can be conservative and does not include any partial plastic stress

distribution and should only be used when interaction on the basis of

resistancesNRd,MRdandVRdcannot be carried out.

2 2 2

x,Ed z,Ed x,Ed z,Ed Ed

y M0 y M0 y M0 y M0 y M0

3 1,0f f f f f

Ultimate Limit States: Verification for Section Resistance
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


73/130


Verification is carried out where appropriate for sections at the ultimate

limit state in relation to member forces and moments: tension resistance, (NEd /Nt,Rd 1,0) Clause 6.2.3 compression resistance, (NEd /Nc,Rd 1,0)Clause 6.2.4 bending resistance, (MEd /Mc,Rd 1,0)Clause 6.2.5 shear resistance, (VEd /Vv,Rd 1,0)Clause 6.2.6 torsional moment resistance, (TEd /TRd 1,0)Clause 6.2.7 combined bending and shear resistance Clause 6.2.8

combined bending and axial resistance Clause 6.2.9 and

combined bending, shear and axial resistanceClause 6.2.10.

Tension Resistance


74/130


Nt,Rdis taken as the smaller of:

(a) yielding of the gross-cross-section to prevent

excessive deformation of the member.

or

(b) ultimate resistance of the net cross-section at

holes for fasteners.

The 0,9 enabled the harmonization of the Mfactor with that used for the

resistance of other connecting parts, i.e. bolts, welds etc. (M0toM7)

Anet is the gross-area less appropriate deductions for all holes and other

openings.

y

pl,RdM0

Af

N

net uu,Rd

M2

0,9A f

N


75/130

Bending Resistance


76/130


Mc,Rdis taken as follows:

(a) for Class 1 or Class 2.

(b) for Class 3 cross-sections.

(c) for Class 4 cross-sections.

Fastener holes in the tension flange may be ignored provided that for the tension

flange: (see Clauses 6.2.5(4)/(5)).

Except for oversize and slotted holes and provided that they are filled with

fasteners, no allowance need be made in the compression zone for holes,.

pl y

c,Rd p,Rd

M0

W fM M

el,min y

c,Rd el,Rd

M0

W fM M

eff,min y

c,Rd el,RdM0

W fM M

f yf,net u

M2 M0

0,9 A fA f

Shear Resistance


77/130


Vc,Rdis taken as follows:

whereAvis the shear area, e.g. for rolled Iand Hsections:

Av= A2btf+ (tw+ 2r)tf hwtw

is a shear area factor to allow for an increase due to strain hardening.

A value of = 1,2 is given in EN 1993-1-5 for steel grades up to and

including S 460.

In the UK National Annex a value of =1,0 is to be taken for all gradesof steel.

Shear buckling need not be checked for unstiffened webs if

v y

c,Rd p,Rd

M0 3

A fV V

w

w

72h

t

Torsional Moment Resistance


78/130


TRdis taken as follows:

whereTt,Ed andTw,Edare the St.Venant torsion and the warping torsion

respectively.

As a simplification for closed hollow cross-sections (i.e. those with high

torsional rigidities) torsional warping can be neglected. For open sections

e.g. IofHsections (i.e. those with low torsional rigidities), the St. Venanttorsion may be neglected.

Torsion combined with bending, shear and axial forces are also covered.

Rd

Ed t,Ed w,Ed

is the torsional resistance of the cross-sectionTT T T

Combined Shear Force and Torsional Moment Resistance
http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


79/130


The design shear force should satisfy the following expressions using a

reduced plastic shear resistance: where:

forIand Hsections:

for a channel section:

for a structural hollow section:

Ed

pl,T,Rd

1,0V

V

t,Edpl,T,Rd pl,Rdy M01 1,25 3V Vf

t,Ed w,Ed

pl,T,Rd pl,Rd

y M0 y M0

11, 25 3 3

V Vf f

t,Edpl,T,Rd pl,Rdy M01 3V Vf

Combined Bending and Shear Resistance
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


80/130


g

In most cases the effect of the shear force on the moment of

resistance can be neglected i.e. whenVEd

< 0,5Vc,Rd

In cases where this is not satisfied there are two options:

1 Use a reduced yield strength for the shear area to determine the

reduced moment of resistance, i.e.fy,reduced = (1 )fywhere

2 For I-sections with equal flanges and bending about the major

axis: and Aw=hwtw

2

Ed

pl,Rd

21

V

V

2w

pl,y y

wy,V,Rd y,c,Rd

M0

4

AW f

tM M

Combined Bending and Axial Resistance


81/130


g

ForClass 1and Class 2cross-sections:

MEd MN,Rd whereMN,Rd is defined for a several different cross-sectionswithout fastener holes.

For Class 3 cross-sections the maximum longitudinal stress induced

(allowing for fasteners holes) by the combined actions must satisfy:

. A conservative alternative may be used for Class 1, Class 2

and Class 3 cross-sections as follows:

This provides a rapid, approximate solution.

y

x,Ed

M0

f

y,Ed z,EdEd

Rd y,Rd z,Rd

1,0M MNN M M

Combined Bending and Axial Resistance


82/130


For Class 4 cross-sections the same limit for longitudinal stress applies

using the effective section properties where appropriate

A conservative alternative to the above criterion may be used as follows:

yx,Ed

M0

f

y,Ed Ed Ny z,Ed Ed NzEd

eff y M0 eff,y,min y M0 eff,z,min y M0

1,0M N e M N eN

A f W f W f

Combined Bending, Shear and Axial Resistance
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


83/130


(1) Where shear and axial force are present, allowance should be made for the

effect of both shear force and axial force on the resistance moment.

(2) Provided that the design value of the shear force VEddoes not exceed 50% of

the design plastic shear resistanceVpl.Rdno reduction of the resistances defined

for bending and axial force in 6.2.9 need be made, except where shear buckling

reduces the section resistance, see EN 1993-1-5.

(3) WhereVEdexceeds 50% ofVpl.Rdthe design resistance of the cross-section to

combinations of moment and axial force should be calculated using a reduced

yield strength (1 )fyfor the shear area where = (2VEd/Vpl.Rd 1)2 andVpl,Rd

is obtained from 6.2.6(2).

Note:Instead of reducing the yield strength the plate thickness of the relevant part

of the cross-section may be reduced.

Buckling Resistance


84/130

copyright protected

Types of buckling:


Local buckling Flexural buckling

Plate buckling

Shear buckling

Distorsional buckling

P

P

Torsional buckling Torsional -flexural buckling

Snap buckling

Figure 21

Lateraltorsional buckling

Buckling ResistanceLocal Buckling
http://www.mech.uwa.edu.au/DANotes/buckling/intro/cylinderBIG.jpeghttp://www.mech.uwa.edu.au/DANotes/buckling/intro/boxGirderBIG.jpeghttp://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


85/130

copyright protected

Section Classification:


Rotation

Class 2

Mp

Me

MM

oment

Class 1

Class 3

Class 4

Sections which have full plastic moment

and hinge rotation capacity.

Sections which have full plastic

moment capacity but not sufficient hinge

rotation capacity.

where:

Mp= plastic moment of resistance

Me= limiting elastic moment of resistance

M = elastic moment of resistance

Local buckling prevents development of

the plastic moment capacity.

Local buckling prevents the development of the yield

stress in one or more elements of the cross-section.

Figure 22

fy

fy

fy

fy

fy

fy

< fy

< fy

Class 1 Class 2 Class 3 Class 4

Buckling ResistanceLocal Buckling (cont.)


86/130

copyright protected

Section Classification:


Figure 23

Note:

c is the flat

portion of the

plate and the

base stressfy = 235 MPa

Buckling ResistanceClass 4 sections


87/130

copyright protected

Effective section properties: effective widthbeffof planar elements


beff= ( b)where, the reduction factor, is dependent on

the plate non-dimensional plate slenderness

Effective cross-sections for members

in compression

Figure 24

y

p

cr

wheref

p

Buckling ResistanceSlender sections in Compression


88/130

copyright protected

Effective section properties:


In doubly-symmetric sections the position

of the neutral axis does not change and

hence:

Nb,Rd=( Aefffy)/M1In singly-symmetric cross-sections, or

asymmetric cross-sections the formation of

effective holes may lead to a shift in the

position of the neutral axis,eN.

The compressive load (NEd), is then eccentric

to the effective cross-section neutral axis and

will cause a secondary bending moment:

M = (NEd eN)The section should be checked for a

combined stress conditionFigure 25

Buckling ResistanceSlender sections in Bendingi i


89/130


EN 1993-1-5:

Table 4.1:

Internal elements

Table 4.1:

Internal elementsTable 4.2:

Outstand elements

Table 4.2:

Outstand elements

Note:the change in the position

of the neutral axis in each case.

Effective section properties:

Figure 26

compression zone

e

Buckling ResistanceSlender sections in Bendingi i


90/130


Effective section properties:EN 1993 -1- 5: 2006

Section 4.4

Effective areas for slendercross-sections

Figure 27Figure 28

1st. term is the von Karman contribution forbuckling of an ideally perfect plate.

2nd. term is to allow for out-of-plane imperfections,

residual stresses and interaction between yielding

and plate buckling.

Internal compression elements

Buckling ResistanceEffective section


91/130


b

hf

hw

tw

1

2

Non-effective zones

-ve - tension

+ve - compression

hf

Figure 29

Verification for Buckling Resistance


92/130


Verification is carried out where appropriate for sections at the ultimate

limit state in relation to:

flexural buckling, (NEd /Nb,Rd 1,0) Clause 6.3.1 lateral torsional buckling, (MEd /Mb,Rd 1,0)Clause 6.3.2 combined bending and axial compression, Clause 6.3.3

y,Ed y,Ed z,Ed z,EdEdyy yz

y Rk y,Rk z,Rk

LT

M1M1 M1

y,Ed y,Ed z,Ed z,EdEdzy zz

z Rk y,Rk z,R k

LTM1 M1M1

1 0

1 0

M M M MNk k ,

N M M

M M M MN k k ,N M M

Buckling ResistanceFlexural Buckling


93/130


Nb,Rdis taken as the smaller of:

(a) for Class 1, Class 2 or Class 3 cross-sections.

or


whereAeff is the effective cross-sectional area determined in accordancewith EN 1993-1-5 and is a reduction factor for flexural, torsional orflexural torsional buckling.

yb,Rd

M1

AfN

eff y

u,Rd

M1

A fN



94/130


Reduction Factor:

where for Class 1, 2 and 3 cross-sections,

for Class 4 cross-sections,

and is the non-dimensional slenderness.

is an imperfection factor which depends on the shape of the column cross-section, the axis of buckling the fabrication process and the steel grade.

The value of can also be obtained from buckling curves given in the code.

2

2 2

1 but 1,0 where = 0,5 1+ 0,2

y

cr

Af

eff y

cr

A f

2

cr 2cr

EI

L

Not given in EC3



95/130


Typical Stress/Slenderness Curve

EC3 - Euler slenderness 1 = (E/fy)0,5 = 93,9(assuming E= 210 103 MPa and fy = 235 MPa)

Slenderness

fy

Failure by

bucklingFailure by

yielding

Euler buckling

curve

P

1

Plastic buckling

Local and flexural buckling

Figure 30



96/130

copyright protected96 Dr. W.M.C. McKenzie

Figure 31

EC3Non-dimensional buckling curve

Safe lower-bound

design curve in EC3

non-dimensional slenderness = ( /1)

1,0

= /fyP

1,0

* *

*

*

*

*

*

*

*

** *

*

*

*

*

*

* *

**

*

***

*

*

*

**

Failure predicted by Euler

Actual test results

0,2

Typical Stress/Non-dimensional Slenderness Curve

Buckling ResistanceCritical Buckling Length


97/130


The only advice given in EC 3

regarding the buckling lengths of

members is in the informative

Annex BB.

In the absence of further information it

is likely that UK engineers will adopt

the effective length values given in

BS 5950: Part 1

Figure 32

Buckling ResistanceBS5950 Buckling Lengths


98/130


Figure 33

T pical Red ction Factor/Non dimensional Slenderness C r e

Buckling ResistanceBuckling Curves


99/130


Figure 34

Typical Reduction Factor/Non-dimensional Slenderness Curve

For non-dimensional slenderness values 0,2 orNEd/Ncr 0,04 buckling

effects may be ignored and only cross-section checks are required.

Tables given in BS 5950 representing the buckling curves

Buckling ResistanceBuckling Curves


100/130


Figure 35

Tables given in BS 5950 representing the buckling curves

Buckling ResistanceTorsional and Torsional-flexural Buckling


101/130


Figure 36

Torsional and torsional-flexural

buckling is generally significant in

cold-formed sections since they are

fabricated from relatively thin

material and are of open section.

Ncr = Ncr,TF but < Ncr,T.

The relevant buckling curve is the

one associated with thez-zaxis.

Single open sections

Open built-up sections

Closed built-up sections

Typical forms of sections for cold-formed members

Buckling ResistanceLateral Torsional Buckling


102/130


102

MbRdis taken as the smaller of:

(a) for Class 1, Class 2 cross-sections.


(c) for Class 4 cross-sections.

whereLTis the reduction factor for lateral torsional buckling and theWyisthe appropriate plastic, elastic or effective section modulus.

yb,Rd LT pl,y

M1

fM W

y

b,Rd LT el,y

M1

fM W

y

b,Rd LT eff,y

M1

fM W

fy

fy

fy

fy

< fy

< fy



103/130


103

Reduction Factor:LT1. General case:

The general case may be applied to all common section types including

rolled sections, plate girders, castellated and cellular beams. The buckling

curves given in Figure 6.4 of EC 3 can be used with to determineLToralternatively Equation (6.56) may be used.

2. Rolled sections or equivalent welded sections (i.e. same size?)In this case the value ofLTis determined using Equation (6.57) and may bemodified to take into account the moment distribution between the lateral

restraints.

LT


No need to check lateral torsional buckling


104/130


104

The general case is less favourable than the one for rolled and equivalent

sections and the plateau is longer potentially offering significant savings.

1,0

0,8

0,6

0,4

0,2

2,01,51,00,50

Rolled and equivalent

welded sections

(Clause 6.3.2.3)

General case

(Clause 6.3.2.2)Red

uctionfactor-LT

Slenderness -LT

No need to check lateral torsional buckling

for below the values indicated.

(Note: curves shown are indicative only)

Figure 37

Reduction Factor LT

Buckling ResistanceLTB: General Case


105/130

copyright protected

Reduction Factor LT

where:

Mcr is the elastic critical moment for elastic bucklingFormulation is not given in EC3

LTis an imperfection factor given in Table 6.3 of EN 1993-1-1

The evaluation ofMcr is considered textbook material and there is a lack of

consensus on the true value. EN 1993 merely states that Mcr is based on the gross

cross-sectional area and takes into account the loading, the real moment

distribution and the lateral restraints.


LT LT2 2

LT LT LT

1 but 1,0

2LT LT LT LT= 0,5 1+ 0,2

y yLT

cr

W f

M

El ti iti l t M



106/130

copyright protected

Elastic critical momentMcr

The elastic critical moment Mcr at which lateral torsional buckling is induced is

dependent on a number of variables one of which is the critical buckling length Lcr.

No guidance is given in EC3 regarding calculatingLcr. or the requirements for the

lateral restraints (?) refer to BS 5950.

It is generally assumed that the standard conditions of restraint at the end of a beam

are:

restraint against lateral movement,

restraint against rotation about the longitudinal axis and

the beam is free to rotate in plan.




107/130


107

Figure 38L cr

L cr

L cr

Intermittent restraint provided

by secondary beams

Note:In Clauses 4.3.2 and 4.3.3 of BS 5950: Part 1 it is required that intermediate lateral

restraints are required to be capable of resisting a total force of not less than 2,5% of

the maximum design axial force in the compression flange within the relevant span,

divided between the intermediate lateral restraints in proportion to their spacing.

Buckling ResistanceLTB: Elastic Critical Moment


108/130


108

Evaluation ofMcr

The elastic critical moment for LTB of a beam of uniform symmetricalcross-section with equal flanges, under standard conditions of restraint at

the ends, loaded through the shear centre and subject to a uniform moment

throughout is given by:

0,5

22w crz

cr 2 2zcr z

where2 1

TI L GI EI E

M GIL EI

M M

LM MFundamental case

= 1,0

Figure 39
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


109/130

Elastic critical moment for lateral torsional buckling factor -C1

= +1,0 C1 = 1,000


110/130


110

= 0,75 C1 = 2,57

= 1,0 C1 = 2,55

= +0,75 C1 = 1,14

= +0,50 C1 = 1,31

= +0,25 C1 = 1,52

= 0 C1 = 1,77

= 0,50 C1 = 2,33

= 0,25 C1 = 2,05

UDL pinned supports

C1 = 1,046

C1 = 1,127

C1 = 2.578

C1 = 1,348

C1 = 1,683

UDL fixed supports

Central point load

pinned supports

Central point load

fixed supports

span point loadsFigure 40


Th l l i h d l d di i b i d


111/130


111

The values relating to the end moment load conditioncan be estimated

using the following equation*:

C1 1,881,4 + 0,522 2,70

*

Galambos, T.V. (ed.) (1998)

Guide to Stability Design Criteria for Metal Structures,

5th. edn. Wiley, New York.

Figure 41-1,0 -0,75 -0,50 -0,25 0,0 0,75 1,00,25 0,50

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

Ratio of end moments -

C1

more exact solution

approximate solution

cut-off value


Th l l i d bl i i b b i d f h


112/130


112

The values relating to doubly symmetric sections can be obtained from the

NCCI: SN003a-EN-EU. This NCCI gives the expression of the elastic

critical moment for doubly symmetric cross-sections. Values of the factors

involved in the calculation are given for common cases. For a beam under

a uniformly distributed load with end moments or a concentrated load at

mid-span with end moments, the values for the factors are given in graphs.

L is the length between points which have lateral restraintkis an effective length factors referring to end rotation about z-z

kw are effective length factors referring to end warping

zg is the distance between the point of load application and the shear centre.

Note :for doubly symmetric sections, the shear centre coincides with the centroid.

2 22

2crwzcr 1 2 22 2

z zcr

T

g g

w

kL GI IEI kM C C z C z

k I EIkL

Figure 42


NCCI: SN003a EN EU (see http://www access steel com/)
http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


113/130


113

NCCI: SN003a-EN-EU. (see http://www.access-steel.com/)

Figure 43

Graphs to determine C1 and C2 values for UDLs and mid-span point

loads combined with end moments.

Buckling ResistanceLTB: Elastic Critical MomentThe value ofMcrcan also be calculated using theLTBeamsoftware which
http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/


114/130

copyright protected


can be downloaded from http://www.cticm.com FREE

Figure 44

Buckling ResistanceLTB: Rolled Sections andEquivalent Welded Sections
http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.cticm.com/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


115/130

copyright protected

Reduction Factor LT

where: and as before.

In the UK National Annex:

= 0,4 for rolled sections and 0,2 for equivalent welded sections,

= 0,75 for rolled sections and 1,0 for equivalent welded sections

The imperfection factor LTis obtained from Table 6.3. The Table 6.4 values for

selection of the appropriate buckling curve have been modified in the UK N.A.


Equivalent Welded Sections

LT 2 2LT LT LT

2LT

1

1,0

1

2LT LT LT LT,0 LT= 0,5 1+ y y

LTcr

W f

M

LT,0

Do not use the buckling curves given in

Figure 6.4 of the code, i.e calculate LT.



116/130

copyright protected

The selection of the appropriate buckling curve: EN 1993-1-1


Equivalent Welded Sections

The selection of the appropriate buckling curve: UK N.A. to EN 1993-1-1

Figure 45



117/130

copyright protected

The modification factorfto be applied to LT:The reduction factor may be modified to take into account the shape of the

bending moment diagram between the restraints, i.e.

f= 1 0,5(1 kc)[1 2,0( 0,8)2] 1,0 wherekcis given in Table 6.6

In the UK Annex

From UK N.A.


LTLT,mod 1,0

f

LT

c1

1k

C

Figure 46

Buckling ResistanceCombined Bending andAxial Compression


118/130

copyright protected


pInteraction Equations:

The My,Edand Mz,Edterms allow for the additional moment which occurs due to

the shift in the neutral axis when using effectivecross-sectional area for Class 4

cross-sections.

Values for the interaction factorski,jfor the formulae can be determined as indicated

in Annex A orAnnex B.they are very complex and time consuming to evaluate.

y,Ed y,Ed z,Ed z,EdEd

yy yzy Rk y,Rk z,Rk

LT

M1M1 M1

y,Ed y,Ed z,Ed z,EdEdzy zz

z Rk y,Rk z,R k

LTM1 M1M1

1 0 Equation (6.61)

1 0 Equation (6.62)

M M M MN

k k ,N M M

M M M MNk k ,

N M M

Buckling ResistanceCombined Bending andAxial CompressionAnnex A:


119/130

copyright protected


Figure 47

Buckling ResistanceCombined Bending andAxial CompressionAnnex B:


120/130

copyright protected


Figure 48

Buckling ResistanceCombined Bending andAxial Compression


121/130

copyright protected


UK NA to EN 1993-1-1:

Figure 49

Buckling Resistance Combined Bending andAxial Compression for Columns in SimpleC t ti


122/130

copyright protected

Dr. W.M.C. McKenzie

122

Construction

NCCI: SN048b-EN-GB

Figure 50

Buckling Resistance Combined Bending and AxialCompression for Columns in Simple Construction


123/130

copyright protected

Dr. W.M.C. McKenzie

123

NCCI: SN048b-EN-GB

Figure 51

Buckling Resistance Combined Bending and AxialCompression for Columns in Simple Construction


124/130

copyright protected

Dr. W.M.C. McKenzie

124

NCCI: SN048b-EN-GB

Figure 52

Serviceability Limit States: Verification for Deflection

For characteristic combinations: EN 1990:2002


125/130

copyright protected

Dr. W.M.C. McKenzie

125

EN 1993-1-1 indicates that serviceability limit states, i.e. deflection,

vibration etc., and their associated loading/analysis models should be

agreed with the client and specified for a project. Reference shouldbe made to the National Annex for any appropriate limits.

In the UK N.A. information is given relating to:

vertical deflections, horizontal deflections and

dynamic effects.

k,j k,1 0,i k,i

1 1

Equation (6.14b)p

j i

G P Q Q

Serviceability Limit States: Verification for Deflection


126/130

copyright protected

Dr. W.M.C. McKenzie

126

Figure 53

Use only the

variable loads

Maintenance of the Eurocodes

CEN is responsible for maintenance of the Eurocodes and has


127/130

copyright protected

p

developed an appropriate strategy for revision and updating.

Maintenance activities deal with:

processing comments from the users,

correction of errors,

technical amendments,

editorial improvements,

resolution of questions of interpretation,

elimination of inconsistencies and misleading statements.

Dr. W.M.C. McKenzie

127

Use of the Eurocodes Outside the EU

Several countries already use the Eurocodes for the revision of


128/130

copyright protected

Several countries already use the Eurocodes for the revision of

existing codes and the creation of new ones.

Several countries are planning the direct implementation of the

Eurocodes.

A number of structural engineers in companies that participatein international projects are using the Eurocodes.

There are Universities outside Europe who are offering courses

on Eurocodes.

Dr. W.M.C. McKenzie

128

Do not underestimate the amount of investment in time and effort required,

particularly if dealing with several materials!

Education/TrainingCPD Provision:


129/130

copyright protected

Professional bodies, e.g. (tonight)

ICE, I.Struct.E., SCI, Concrete Centre, TRADA, BDA

Universities, Colleges etc. e.g. recent Edinburgh Napier short courses

Web Resources, e.g.

http://eurocodes.jrc.ec.europa.eu

http://www.cticm.com

http://www.access-steel.com/

Textbook Publications & Software e.g. Thomas Telford Design Guides and

The Behaviour and Design of Steel Structures to EC3 by N S Trahair et al.

ISBN 978-0-415-41866-9,LTbeamsoftware etc.

Dr. W.M.C. McKenzie

129

The Future

Exciting and
http://eurocodes.jrc.ec.europa.eu/http://www.cticm.com/http://www.access-steel.com/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpghttp://www.access-steel.com/http://www.access-steel.com/http://www.access-steel.com/http://www.cticm.com/http://eurocodes.jrc.ec.europa.eu/http://www.napier.ac.uk/http://eurocodes.jrc.ec.europa.eu/images/Eurocodes_logo1.jpg


130/130

BS 449, BS 5950

Slide Rule

Eurocodes!!!!

Note Book!!

Exciting and

challenging

opportunities for

innovation using

the worlds mostadvanced design

codes and

sophisticatedsoftware analyses.Th k Y

Structural Steelwork

Documents

Transcript of Structural Steelwork