9.2 STRUCTURAL STEEL 9.2.1 The primary structure and any critical temporary works like lifting attachments, spreader bars and seafastenings shall be of high quality structural steelwork with full material certification and NDT inspection certificates showing appropriate levels of inspection. It shall be assessed using the methodology of a recognised and applicable offshore code including the associated load and resistance factors for LRFD codes or safety factors for ASD/WSD codes. 9.2.2 Traditionally AISC has also been considered a reference code, e.g. by API RP2A. Although specifically not recommended by API 22nd edition, if the ANSI / AISC 360-10 American National Standard “Specification for Structural Steel Buildings” of June 2010 (in the AISC 14th edition) is used, the allowables shall be compared against member stresses determined using a load factor on all loads (dead, live, environmental, etc.) of no less than those detailed in the following Table 9-1. Table 9-1 Load Factors for use with AISC 14th Edition Type WSD option LRFD Option To be used only with the loading criteria given in the GL Noble Denton Guidelines Limit State 1 (LS1): 1.00 1.60 Limit State 2 (LS2): 0.75 1.20 Note: The load factor of 0.75 for the WSD/LS2 case arises because the basic allowable stress in AISC WSD 14 th edition is 0.6*yield and the traditional 1/3 increase to 0.8*yield (i.e. to 0.6*yield*4/3) for environmental load cases is not included. As an alternative, the load is multiplied by 3/4 and used with the standard allowable of 0.6*yield in order to achieve the safety levels that have been used and accepted over many years. 9.2.3 Stress in fillet welds for brackets loaded by a force acting in a direction parallel to the weld bead shall be assessed using the method presented in Appendix A. The allowables shall be compared against member stresses determined using a load factor on both dead and live loads of no less than LS1: 1.40 LS2: 1.05 9.2.4 Any load case may be treated as a gravity-load dominated limit state (LS1). 9.2.5 The infrequent load cases, generally limited to survival and damaged cases, including design cases for weather-restricted operations where an Alpha factor according to Section 7.4.8 is to be applied, may be treated an LS2, environmental load dominated, case. This does not apply to: Steelwork subject to deterioration and/or limited initial NDT unless the condition of the entire loadpath has been verified, for example the underdeck members of a barge or vessel. Steelwork subject to NDT prior to elapse of the recommended cooling and waiting time as defined by the Welding Procedure Specification (WPS) and NDT procedures. In cases where this cannot be avoided by means of a suitable WPS, it may be necessary to increase the strength or impose a reduction on the design/permissible seastate. Steelwork supporting sacrificial bumpers and guides. Spreader bars, lift points and primary steelwork of lifted items. Structures during a load-out. 9.2.6 The design of non-tubular connections shall be in accordance with an appropriate standard such as AISC Ref. [13], using a consistent safety format and factors. 9.3 FILLET WELDS 9.3.1 Appendix A gives the requirements for checking fillet welds.
Добавлено спустя 6 минут 42 секунды: Re: Расчёт прочности сварных швов при крепеже груза и конструкци Скачай и посмотри Нобл Дентон руководство GENERAL GUIDELINES FOR MARINE PROJECTS 0001/ND Это используется для морских гарантийных инспекторов при проверке расчетов для застрахованных грузов, в частности при перевозке буровых вышек и прожект карго на палубе. В приложении А есть полный расчет катета сварки и длины сварочного шва. Правда там разобраться довольно сложно, по крайней мере мне
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