弯扭箱形钢构件受拉性能与破坏机理

弯扭箱形钢构件是指在箱形钢构件的基础上,2个端部绕构件轴线发生扭转、沿构件纵向发生弯曲的复杂构件。因优美的建筑造型,弯扭箱形钢构件近年来在国内外的大跨度空间结构中逐步得到应用,然而目前对于弯扭箱形钢构件的受拉性能和破坏机理尚缺乏系统性的研究。利用ABAQUS有限元程序建立了受拉作用下弯扭箱形钢构件的数值分析模型,通过试验验证了计算模型的准确性。研究了钢材强度、弯曲曲率、截面相对扭转角和钢板厚度等参数对弯扭箱形钢构件受拉承载力的影响规律。分析结果表明:随着钢材强度和钢板厚度的增加,弯扭箱形钢构件的屈服受拉承载力明显提高;构件弯曲程度和截面相对扭转角的增大会明显降低其屈服受拉承载力。另外,还分析了弯扭箱形受拉钢构件的破坏模式和受力机理,研究结果可为实际工程中弯扭箱形钢构件的设计和应用提供参考依据。

The Tensile Behavior and Failure Mechanism of Steel Bending-Torsion Box-Section Members

Bending-torsion box-section member is a box-section member that twists around the centroid axis and bends longitudinally.Nowadays,bending-torsion box-section member has been widely applied in large-span spatial structures at home and abroad because of its aesthetical performance in shape,but the studies on the tensile behavior and failure mechanism of bending-torsion box-section member are limited.This paper provides a numerical model of bendingtorsion box-section members under tension by ABAQUS software,and then verified a finite element(FE)model according to existing experiments.Following this,the parameters of steel strength,bending degree,relative twist angle and steel plate thickness are studied to obtain their effects on the tensile yield bearing capacity of the bending-torsion box-section member.The results show that the tensile yield bearing capacity increases with the increase of the steel strength and the steel plate thickness.While the increase of the bending degree and the relative twist angle results in the decrease of the tensile yield bearing capacity.The failure modes and stress mechanism of bending-torsion boxsection tensile members are analyzed.The results can provide a reference for the design and application of bendingtorsion box-section tensile members in engineering practice.