BS NA EN 1993 1 9 UK National Annex to Eurocode 3 Design of steel structures Fatigue United Kingdom of Great Britain and Northern Ireland In order to promote public education and public safety, equal[.]
Un i t e dKi n g d o mo fGr e a t Br i t a i na n dNo r t h e r nI r e l a n d ≠ EDI CTOFGOVERNMENT± I no r d e rt op r o mo t ep u b l i ce d u c a t i o na n dp u b l i cs a f e t y ,e q u a lj u s t i c ef o r a l l ,ab e t t e ri n f o r me dc i t i z e n r y ,t h er u l eo fl a w,wo r l dt r a d ea n dwo r l d p e a c e ,t h i sl e g a ld o c u me n ti sh e r e b yma d ea v a i l a b l eo nan o n c o mme r c i a l b a s i s ,a si ti st h er i g h to fa l lh u ma n st ok n o wa n ds p e a kt h el a wst h a t g o v e r nt h e m BS NA EN 1993-1-9 (2005) (English): UK National Annex to Eurocode Design of steel structures Fatigue Nu l l iv e n d e mu s ,n u l l in e g a b i mu sa u td i f f e r e mu sRe c t u ma u tJu s t i c i a m Wewi l ls e l lt on oma n ,wewi l ln o td e n yo rd e f e rt oa n yma ne i t h e rJu s t i c eo rRi g h t MAGNACARTA( 97 ) NA to BS EN 1993-1-9:2005 NATIONAL ANNEX UK National Annex to Eurocode 3: Design of steel structures Part 1-9: Fatigue ICS 91.010.30 _® British Standards NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITIED BY COPYRIGHT LAW NA to BS EN 1993-1-9:2005 Publishing and copyright information The BSI copyright notice displayed in this document indicates when the document was last issued © BSI 2008 ISBN 978058054971 The following BSI references relate to the work on this standard: Committee reference B/525/10 and B/525/31 Draft for comment 07/30128138 DC Publication history First published May 2008 Amendments/corrigenda issued since publication Date Text affected NA to BS EN 1993-1-9:2005 Contents Introduction NA.l NA.2 NA.3 Scope Nationally Determined Parameters References to non-contradictory complementary information Bibliography List of tables Table NA.l - Minimum required fatigue strength Table NA.2 - Recommended YFf for safe life design Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages to 6, an inside back cover and a back cover © BSI 2008 • NA to BS EN 1993-1-9:2005 ii • © BSI 2008 This page deliberately left blank NA to BS EN 1993-1-9:2005 National Annex (inforntative) to BS EN 1993-1-9:2005, Eurocode - Design of steel structures - Part 1-9: Fatigue Introduction This National Annex has been prepared by BSI Subcommittee B/525/1 0, Bridges, in consultation with B/525/31, Structural use of steel In the UK it is to be used in conjunction with BS EN 1993-1-9:2005 NA.l Scope This National Annex gives: a) the UK decisions for the Nationally Determined Parameters described in the following clauses and subclauses of BS EN 1993-1-9:2005: 1.1(2) Clause 2(2) Clause 2(4) Clause 3(2) • Clause 3(7) • Clause 5(2) • 6.1(1) 6.2(2) • 7.1(3) • 7.1(5) • Clause B( 4) b) references to non-contradictory complementary information NA.2 Nationally Determined Parameters NA.2.1 NA.2.1.1 Material and execution tolerances and information on inspection requirements for fabrication [BS EN 1993-1-9:2005, 1.1(2)] Material and execution tolerances Until such time as BS EN 1090-2 is published, the rules are applicable to structures where execution conforms to either BS 5400-6: 1999 for bridges or BS 5950-2:2001 for buildings Note that, where BS 5400-6:1999 makes reference to minimum class requirements D, E and F, Unspecified, these may be taken to refer to a minimum requirement for the value of Acre = 91 N/mm2, 80 N/mm2, 63 N/mm2 and 56 N/mm2 respectively For additional guidance see NA.3 â BSI 2008 ã NA to BS EN 1993-1-9:2005 NA.2.1.2 Information on inspection requirements for fabrication For the safe life method of assessment, special inspection and testing requirements for welds, cut edges and plain surfaces should be provided on drawings for all applications where the minimum required fatigue strength exceeds the relevant value of dO"c in Table NA.1 Table NA.l Minimum required fatigue strength Detail type according to BS EN 1993-1-9 Fatigue strength levels, Llac Table Detail numbers N/mm 8.1 8.2 1, 1,2,3,4,5,6,7,10,11 1,2,4,5,7,19 8, 10 3,6 >125 >90 >80 >71 >63 >80 >80 8.3 8.4 8.8 NOTE Minimum 'requi:redjatigue st'rength is the value that would just achieve compliance with BS EN 1993-1-9:2005, Clause For additional guidance see NA.3 NA.2.2 NA.2.2.1 Fatigue loading models [BS EN 1993 1-9:2005, Clause 2(2)] Sources of fatigue loading All sources of fluctuating stress in the structure should be identified and should be obtained from the relevant parts of BS EN 1991 For fatigue loading not covered in BS EN 1991 the following should receive particular attention: a) superimposed moving loads, including vibrations from machinery in stationary structures; b) environmental loads such as wind, waves, etc.; c) acceleration forces in moving structures; d) temperature changes Where no published data for live loading exist, the partial safety factors for fatigue load intensity for safe life design should take into account the degree of confidence in the prediction of the design load spectrum from the available data Recommended values of 1Ff are given in Table NA.2 ã â BSI 2008 NA to BS EN 1993-1-9:2005 Table NA.2 Recommended "IFf for safe life design Number of standard Value of 1Ff deviations on load intensity standard deviations A) + standard deviations A) °+1 1,5 1,4 1,3 1,2 +2 1,1 1,0 A) Number of standard deviations on number of cycles Reference to guidance on determination of specific fatigue loading models is given in NA.3 NA.2.3 Determination of fatigue strength from tests [BS EN 1993-1-9:2005, Clause 2(4)] Reference to guidance on determination of specific fatigue strength data from tests is given in NA.3 NA.2.4 Provisions for in-service inspection programmes [BS EN 1993-1-9:2005, Clause 3(2)] In the event that the damage tolerant assessment method is to be used, the following provisions apply a) The designer should be satisfied that the Maintaining Authority for the structure is aware of the practical requirements and the likely costs of provision of access, the inspection itself, possible repair and temporary loss of service, prior to approval being given b) Any potential fatigue crack initiation sites should be on or close to a surface which will be readily accessible in service c) The method or methods of inspection should be specified for each potential fatigue initiation site Inspection for fatigue cracking requires more sophisticated techniques than are used for normal principal inspections d) The minimum size of detectable fatigue crack should be specified for each initiation site, taking into account the capability of the methods in c) e) The maximum tolerable size of fatigue crack Cusing fracture mechanics) for fracture under ULS loading should be calculated f) The time taken for the fatigue crack to grow from the minimum detectable size in d) to the fracture tolerable size in e) should be calculated by fracture mechanics using upper bound crack growth data and the upper bound fatigue loading g) The maximum interval between inspections should be not more than half the time calculated in f) This may be less than the interval between principal inspections h) Guidance should be given on any requirements for taking the structure out of service or increasing the inspection frequency in the event that cracks are detected â BSI 2008 ã NA to BS EN 1993-1-9:2005 NA.2.5 NA.2.5.1 i) Viable schemes should be drawn up for repair, strengthening or replacement of the member where fatigue cracks have been detected j) A maintenance manual should be provided to the maintaining authority at the time of commissioning of the structure, giving details of the items in c), g), h) and i) Assessment method, definition of class of consequence and partial factor for fatigue strength [BS EN 1993-1-9:2005, Clause 3(7)] Assessment method Steel structures subject to fatigue loading should be assessed using the safe life method, unless otherwise agreed with the Maintaining Authority NA.2.5.2 Classes of consequences Unless otherwise specified in the project specification, all steel structures subjected to fatigue should be consequence class CC2 according to BS EN 1990:2002, Annex B If consequence class CC1 or CC3 is specified, the appropriate KFI factors should also be applied The values in BS EN 1990:2002, Annex B are recommended NA.2.5.3 Partial factor for fatigue strength For steel structures assessed for safe life using the detail categories given in BS EN 1993-1-9:2005, Tables 8.1 to 8.10, and the fatigue loading in BS EN 1991-2, a value ofYMf = 1.1 should be used irrespective of consequence class in BS EN 1990:2002 For additional guidance see NA.3 NA.2.6 Stress limitations for Class sections [BS EN 1993-1-9:2005, Clause 5(2)] The effects of excessive repeated non-linear out of plane deflection in flat panels might be neglected if the slenderness of plates meets criterion (2) of BS EN 1993-2:2006, 7.4 NA.2.7 Use of nominal, modified nominal and geometric stress ranges [BS EN 1993-1-9:2005, Clause 6.1(1)] Reference to guidance on determination of stress ranges is given inNA.3 ã â BSI 2008 NA to BS EN 1993-1-9:2005 NA.2.8 Design value of nominal stress range [BS EN 1993-1-9:2005, Clause 6.2(2)] Where no Ai values are given it is not possible to calculate the value of L\(JE,2' In such cases the verification format should be based on damage accumulation equation A.l, given in BS EN 1993-1-9:2005, A.S(I), and damage accumulation expression A.2, given in BS EN 1993-1-9:2005, A.6(1), using the most comprehensive load model available For additional guidance see NA.3 NA.2.9 Verification of fatigue strength category [BS EN 1993-1-9:2005, Clause 7.1(3)] Verification of a fatigue strength category for a particular application by testing is permitted provided that it is evaluated in accordance with BS EN 1993-1-9:2005, 7.1(3), Note For additional guidance see NA.3 NA.2.10 Fatigue strength categories for details not covered by Tables 8.1 to 8.10 or Annex B [BS EN 1993-1-9:2005, Clause 7.1(5)] Fatigue strength categories for details not covered by BS EN 1993-1-9 should be given for individual projects NA.2.11 NA.2.11.1 Use of Annex A [BS EN 1993-1-9:2005, Clause 8(4)] Loading events Reference to guidance on determining fatigue loading models is given inNA.3 NA.2.11.2 Cycle counting Reference to guidance on the procedure for cycle counting by the reservoir method is given in NA.3 NA.3 References to non-contradictory complementary information Complementary guidance on fatigue is given in PD 6695-1-9 â BSI 2008 ã NA to BS EN 1993-1-9:2005 Bibliography For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies BS 5400-6:1999, Steel, concrete and composite bridges - Part 6: Specification for materials and workmanship, steel BS 5950-2:2001, Structural use of steelwork in building Part 2: Specification for materials, fabrication and erection - Rolled and welded sections PD 6695-1-9, Recommendationsfor the design of structures toBS EN 1993-1-9 BS EN 1990:2002, Eurocode -Basis of structural design BS EN 1991, Eurocode - Actions on structures BS EN 1993-2:2006, Eurocode Part 2: Steel bridges ã â BSI 2008 Design of steel structures- NA to BS EN 1993-1-9:2005 This page deliberntely left blank NA to BS EN 1993-1-9:2005 BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the intemationallevel It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: +44 (0)2089969000 Fax: +44 (0)20 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: +44 (0)20 8996 9001 Fax: +44 (0)208996 7001 Email: orders@bsi-globaLcom Standards are also available from the BSI website at http://www.bsi-globaLcom In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: +44 (0)20 8996 7111 Fax: +44 (0)20 8996 7048 Email: info@bsi-global.com Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: +44 (0)208996 7002 Fax: +44 (0)20 8996 7001 Email: membership@bsi-global.com Information regarding online access to British Standards via British Standards Online can be found at http://www.bsi-global.com/bsonline Further information about BSI is available on the BSI website at http://www.bsi-globaLcom Copyright - - ~ • Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means - electronic, photocopying, recording or otherwise - without prior written permission from BSI British Standards This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained 389 Chiswick High Road London W44AL Details and advice can be obtained from the Copyright & Licensing Manager Tel: +44 (0)20 8996 7070 Fax: +44 (0)20 8996 7553 Email: copyright@bsi-globaLcom .®