考虑局部屈曲影响的H形钢构件在双向压弯作用下的滞回性能研究

Hysteretic behavior of H-section steel members under biaxial bending considering local buckling

由于地震作用是多维的,结构构件在地震作用下将会受到双向弯矩作用,而构件在一个主轴方向的屈服或屈曲会给构件在另一主轴方向的各项性能带来退化。针对H形截面钢构件,设计了一种由万向铰与三个跟动装置组成的三维加载系统,对11个不同宽厚比、轴压比和加载方向组配下的大宽厚比H形截面钢构件进行了双向压弯的滞回试验研究,考察了其破坏模态、滞回曲线及耗能能力等滞回性能。采用ABAQUS软件建立了有限元模型,采用试验结果进行了校核。最后基于试验和有限元分析结果,分析了扭转效应对试件的影响特性。研究结果表明,板件的局部屈曲和塑性变形的相关作用是影响试件滞回响应的重要因素,而影响效果主要取决于板材宽厚比、轴压比和加载方向的耦合作用;扭转效应对所设计的试件影响较小。

Structural members may subject to biaxial bending moments due to the multi-dimensional seismic actions,where the yield or local buckling about one principal axis will lead to mechanical behavior degradations about the other principal axis.A 3D loading system composed of a universal hinge and three sliding devices,was designed to apply the combined axial load and biaxial bending to the H-section steel structural members.The experimental investigation on the cyclic biaxial bending behavior of H-section steel members with larger width-thickness ratios was conducted.The failure mechanism,hysteretic curves,and energy dissipation capacity of 11 specimens were investigated.The specimens were designed with different width-thickness ratios of flanges and webs,axial force ratios,as well as loading directions.Furthermore,the FE models were established by ABAQUS and verified by experimental results.Finally,based on the experimental and numerical analyses,the influence of torsional moment on the specimens was examined.The results show that the hysteretic response of the specimens is strongly influenced by the interaction effect between the local buckling and plastic deformation of the component plates,which is determined by the coupling effect between the width-thickness ratio of plate,axial force ratio,and loading direction.It is indicated that the effect of torsional moment on the specimens can be neglected.