不锈钢焊接工字形截面梁整体稳定性分析

STUDY OF LATERAL TORSIONAL BUCKLING STRENGTH OF STAINLESS STEEL BEAM OF WELDED I-SECTION

基于国内外已有的不锈钢焊接工字形截面梁整体稳定性的计算方法,包括美国SEI/ASCE 8-02中的方法、欧洲EN 1993-1-4中的方法和王元清提出的方法,采用有限元方法对不锈钢焊接工字形截面梁的整体稳定性进行分析,并用不锈钢焊接工字形截面梁已有的试验数据对有限元模型的准确性进行验证,在此基础上,对不锈钢焊接工字形截面梁进行参数化分析。分析表明:对梁整体稳定承载力影响的因素从大到小依次为材料名义屈服强度、荷载类型、截面类型和焊接残余应力;在参数化分析的基础上,提出基于修正正则化长细比的Perry公式型整体稳定系数表达式;将所提出的计算方法、国内外现有的计算方法与试验数据进行了对比,结果表明受试验中边界条件的影响,试验值高于计算方法的计算值,与其他方法相比,所提出的计算方法与有限元计算结果吻合更好,可以用于计算焊接工字形截面梁的整体稳定承载力。

This paper focuses on the lateral torsional buckling strength of stainless steel beam with welded I-section.The existing calculation methods for the lateral torsional buckling strength of stainless steel beam of welded I-section were introduced,including the method in American code SEI / ASCE 8- 02,the method in Eurocode EN 1993- 1-4,and the method proposed by Wang. Finite element model was developed and verified by using the previous test data. Parameter analysis was performed. The effects of parameters on the lateral torsional buckling strength were discussed,and the effect from high to low was the effect of nominal yield strength,the load type,the section type,and the welding residual stresses. Based on the result of parameter analysis,the global buckling factor was expressed in terms of Perry formula with a transformed slenderness ratio. Comparisons between predictions of the proposed method,the existing methods,and test data were conducted. The comparisons indicated that due to effect of the boundary conditions in the test,test results were higher than the calculated ones of all the methods. And the proposed method had a much better agreement with the finite element analysis results than other methods,which could be used for the global buckling resistance predictions.