Copyright Canadian Institute of Steel Construction

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Mabel York
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1 Copyright 017 by Canadian Institte of Steel Constrction All rights reserved. This book or any part thereof mst not be reprodced in any form withot the written permission of the pblisher. Third Edition First Printing, December 015 Second Revised Printing, Janary 017 ISBN PRINTED IN CANADA

2 14) Calclate Becase there is no side thrst, we cannot se the flexre analogy. The eqation 13.6(e) (ii) can be modified for loading other than at the shear centre by sing the following eqation for the eqivalent moment factor. 3 B r R.5 Where is the eqivalent moment factor for the moment distribtion along the laterally nspported length; B is as defined below; the exponent r is 0 for loading throgh the shear centre, -1 for loading at the top flange (to accont for the destabilizing effect of loading a beam at the level of the compression flange) and +1 for loading at the bottom flange (stabilizing effect); R is a factor to accont for doble crvatre loading of mono-symmetric sections, taken as 1.0 for single crvatre between points of lateral spports. B W W B W W Where W Ls ECw GJ and Ls is the laterally nspported length. A simplification is shown in the SSRC Gide (Ziemian 010) where the effects of load height and load condition can be approximated by taking B 1.4. This approach will be sed herein. Then Nmm 07 knm 15) Calclate yr 07. S F, with S minimm yr x y x kn m 6 10 The factor 0.7 was introdced in S16 to accont for residal stresses. See comment by Trahair (011), p ) Calclate L L where r t 11. r t E F b c y 490rt F hw c 11 3 bt cc h c depth of the web in compression y 9

3 b c width of compression flange t c thickness of compression flange r t mm L 511 mm ) Since > yr, calclate r r p p yr L L Lyr L L yr length L obtained by setting yr To find L yr, can be expressed as follows L yr Lyr p L yr, mm, kn m < < 1570, bt close enogh, can be refi ned if necessary 18) Calclate r From step 11, p 797 kn m, p kn m r kn m 517 kn m OK 19) Calclate the strength in bending for the load combination of side thrst, no impact Nmm 839 knm 0) Calclate yr Refer to step 15 yr 1570 knm 93

4 1) Calclate L Refer to step 16 L 511mm ) Since > yr, calclate r r p p yr L L Lyr L L yr length L obtained by setting yr To find L yr, can be expressed as follows L yr Lyr p L yr, mm, kn m ) Calclate r > > < 1570, bt close enogh From step 11, p 797 kn m, p kn m r kn m 517 kn m OK 4) Calclate distribtion of the side thrst Cs by flexral analogy See figres A10 and A11. oment at Shear Centre C s ^ h 33C s Cople, applied to each flange 33C s C s Note: This dimension shold be to the centroid of the top flange, Close enogh in this case. 40 lb Rail Shear Centre C s ( )/109. mm 43-( )/3 mm (See note) Dimensions ronded to the nearest mm /384 mm Figre A10 Distribtion of Side Thrst 94

5 Distribtion of horizontal load applied at shear centre, as a simple beam analogy Cs - to top flange # Cs ^ h - to bottom flange C s fyt (top flange) 118. # knm $ fyb (bottom flange) # knm $ fx 189 kn$ m C s 0.636C s 1.180C s C s Shear Centre C s C s C s Figre A11 oments abot Shear Centre 5) Check overall member strength with impact, no side thrst fx rx + fy ry # # # < 1.0 OK 6) Check stability (lateral-torsional bckling) with impact, no side thrst # # < 1.0 OK 7) Check overall member strength with side thrst, no impact. Becase side thrst prodces calclated y, we are entitled to se the flexre analogy as in step <. OK # # 8) Check stability with side thrst, no impact <. OK # # 9) By clase 13.5(a), check that flanges do not yield nder service load. A qick check shows OK. No frther checks are reqired (see Section 5.10) Conclsion: Section is adeqate in bending. 95

6 Check Local Wheel Spport (a) Check Web Crippling and Yielding (Clase 14.3.) Factored Wheel Load 1.5 x 1.5 x kn Rail, 146 mmdeep 1 1.5:1 Flange, t 30 mm Web, t 16 mm Fillet Weld, 8mm N( x 146) +(5 x 38) 48 mm Figre A1 Web Crippling Under Crane Wheel Check Interior (i) 350 B r kn (i) Governs 08. (ii) B r kn 14.3.(ii) 1000 The factored resistance of 159 kn > kn OK A check at the ends is not necessary becase bearing stiffeners will be sed. (b) Check torsional effects on web nder a wheel load inclding rail eccentricity and side thrst. Factored Vertical Load 15. # 15. # kn, inclding impact Factored moment de to eccentricity # # # 61. knm $ 1000 Factored moment de to side thrst # # 613. knm $ 1000 f knm $ 110

The Open Civil Engineering Journal

The Open Civil Engineering Journal Send Orders for Reprints to reprints@benthamscience.ae 564 The Open Ciil Engineering Jornal, 16, 1, 564-57 The Open Ciil Engineering Jornal Content list aailable at: www.benthamopen.com/tociej/ DOI: 1.174/187414951611564