H形截面钢构件在双向压弯下的极限状态分析

RESEARCH ON ULTIMATE STATE OF H-SECTION STEEL MEMBER UNDER BIAXIAL BENDING

双向压弯构件两主轴方向存在强度、刚度及塑性变形能力等的相互影响作用,目前对由局部失稳控制的H形截面钢构件双向压弯性能的研究非常有限,亟需对此展开研究。通过建立有限元模型,对3个不同宽厚比组配下的H形截面构件双向压弯的非线性性能展开研究。考察了H形构件双向压弯的基本受力特点,分析了由于宽厚比不同导致的两种破坏模式。基于能量守恒原理,提出通过能量拐点的方法确定H形截面钢构件在双向压弯下的极限状态。通过构件截面平均应力发展分析,表明该方法确定的构件极限状态是合理的。

The interactive effects of strength, stiffness and plastic deformation capacity can be obversed at the two main axises of steel members. Since the research on biaxial bending behavior of H-section steel member dominated by local buckling is quite limited, it is necessary to investigate the nonlinear performance of such member. The behavior of three H-section members composed of different plate slenderness under biaxial moments were investigated by numerical analysis. The basic mechanical properties of H-section members under biaxial bending were investigated, where two types of failure modes due to different plate slenderness were analyzed. Based on the energy conservation principle, an approach to determine the ultimate state of H-section members under biaxial bending by the inflection of energy was proposed. The approach was validated through the stress distribution property analysis in the ultimate state.