连续开孔实腹梁整体稳定性计算方法

摘要

为研究腹板开孔H型钢梁在纯弯荷载作用下的整体稳定性,采用翼缘和腹板刚度分离的方法,从理论上推导出带有连续正方形孔洞的H型钢梁的抗侧刚度、自由扭转刚度和翘曲刚度计算方法,得到其弯扭屈曲临界弯矩表达式.利用有限元软件ABAQUS对相同截面不同跨度的H型钢实腹梁在纯弯荷载作用下的弯扭屈曲临界弯矩进行分析,并将有限元模拟结果和规范计算结果进行对比.采用经验证的有限元模型对带有连续正方形孔洞的H型钢梁进行分析,并将有限元模拟结果与推导公式的计算结果进行对比.以现有规范为基础,推导出带有连续正方形孔洞的H型钢梁的弯扭屈曲临界弯矩实用计算公式.结果表明:连续开孔梁实用计算公式具有较高的精确度.%In order to study the overall stability of H-shaped steel girder with multiple holes under pure bending load,the rigidities of flange and web were investigated separately.The design rules for lateral stiffness,warping stiffness and torsional stiffness of H-shaped steel girder with multiple square holes were derived theoretically to obtain the critical moments of flexuraltorsional buckling.Furthermore,the critical moments of flexural-torsional buckling of H-shaped steel girder with same cross-section dimensions and different spans under pure bending load were analyzed by using the finite element software ABAQUS.The results by finite element model were compared with the results by current design code.The H-shaped steel girder with multiple square holes were analyzed by verified finite element model,and the results by finite element model were compared with the results by the derived formulae.The formulae for the critical moments of flexural-torsional buckling of H-shaped steel girder with multiple square holes were proposed based on the current design code.The results show that the practical calculation formula of steel girder with multiple square holes has high accuracy.