焊接箱形截面不锈钢柱相关稳定性能分析

BEHAVIOR OF INTERACTIVE BUCKLING IN WELDED STAINLESS STEEL BOX SECTION COLUMNS

采用有限元法对焊接箱形截面不锈钢柱的局部与整体相关稳定性能进行分析,研究利用板件的屈曲后强度,以实现更为经济合理的构件截面设计。建立了可以准确模拟不锈钢非线性材料力学性能、截面焊接残余应力和构件的局部与整体几何初始缺陷等因素的精确有限元数值模型,并依据试验结果对模型的可靠性进行了验证。基于验证可靠的有限元模型,开展了系统参数分析,同时补充了大量的数值计算数据点。根据得到的试验和有限计算结果,对相关稳定承载力的理论计算方法进行了比较分析,表明现有的方法应用较为复杂,而且可能高估构件的相关稳定承载力。针对奥氏体型和双相型两类不锈钢提出了通用的计算修正系数,给出了新的直接强度法计算公式,经试验与有限元计算结果验证,表明其能够准确计算焊接箱形截面不锈钢柱的相关稳定承载力。

The local-overall interactive buckling behavior of welded stainless steel box section columns was analyzed by using the finite element （FE） method in order to explore the plate post-buckling strength and achieve more economical and efficient sectional design. Elaborated FE models were developed to simulate the performed interactive buckling tests, taking account of the possible influences of nonlinear material properties, welding residual stresses, local and global geometric imperfections. Upon the validation of accuracy for the FE models, systematic parametric studies were carried out, generating supplemental numerical results. The obtained test and numerical results were compared with the theoretical calculation methods, indicating that the theoretical methods may provide overestimated predictions for the interactive buckling capacity. Modified calculation coefficients have been proposed for the austenitic and duplex stainless steel alloys, accompanied by a new direct strength method （DSM） formula, and their accuracy in predicting the interactive buckling capacity of welded stainless steel box section columns has also been verified by the obtained test and numerical results.