形截面压弯钢构件板组弹塑性相关屈曲分析

Plate Assembly Elastoplastic Interactive Buckling Analyses of H Section Steel Members under Compression and Bending

摘要:

建立轴压力和水平荷载作用下焊接H形截面钢构件有限元分析模型以模拟板组弹塑性相关屈曲性能，改变轴压比、翼缘宽厚比、腹板高厚比及翼缘腹板厚度比等参数，进行一系列非特厚实截面钢构件弹塑性局部相关屈曲非线性有限元分析，获得一系列极限弯矩比与这些参数的相关曲线，表明极限弯矩比随轴压比和翼缘宽厚比增大而明显降低.得到精度较高的正则化极限弯矩比拟合公式，基于整体和局部等稳原则导出板组容许宽厚比相关曲线.在某些条件下，钢结构设计规范的翼缘和腹板宽厚比限值可能超出容许宽厚比相关曲线限定的参数范围.

关键词:焊接H形截面; 弹塑性; 相关屈曲; 极限弯矩比; 宽厚比限值

Abstract:

The finite element analysis model of a welded H section steel member subjected to vertical axial compressive force and horizontal load is created to simulate the plate assembly elastoplastic interactive buckling behavior. A series of nonlinear finite element analyses for nonplastic section members with different axial compression ratio, flange widththickness ratio, web heightthickness ratio and flangeweb thickness ratio are performed to evaluate the ultimate moment ratio due to elastoplastic local interactive buckling. A number of correlation curves of ultimate moment ratio versus aforementioned parameters demonstrate that the ultimate moment ratio decreases significantly with increased axial compression ratio and flange widththickness ratio. The normalized fitting formula of ultimate moment ratio is achieved with high accuracy. The allowable widththickness ratio correlation curves are derived on the basis of the principle of simultaneous overall and local interactive buckling. The flange and web widththickness ratio limitations given in the Code for Design of Steel Structures may exceed the parameter regions enclosed by the allowable widththickness ratio correlation curves under certain conditions.

Key words:welded H section; elastoplasticity; interactive buckling; ultimate moment ratio; widththickness ratio limitation