十字形矩形钢管相贯节点平面外抗弯性能研究

Study on out-of-plane flexural behavior of rectangular hollow section cross-type joints

为了研究十字形矩形钢管节点平面外抗弯性能,进行了支主管截面高度比为中等和大的两个节点试件的往复弯矩加载试验和有限元分析,提出用于节点抗弯承载力计算的全屈服线模型,该模型同时考虑了主管表面和侧壁塑性发展.研究结果表明:两个节点最终为焊缝及其附近主管管壁撕裂破坏;高度比大的节点的承载力和耗能能力强于高度比中等的节点,但延性略差;简单屈服线模型低估了节点抗弯承载力15%~30%,全屈服线模型高估了节点抗弯承载力15%~25%,两种模型的平均值、基于全屈服线模型发展而来的参数化计算式均能较好地估计节点抗弯承载力,误差大多在10%以内.

To study the out-of-plane flexural behavior of the rectangular hollow section(RHS) cross-type joints,an experiment of two cross-type joint specimens with medium and large brace-to-chord height ratios(BCHR) under cyclic out-of-plane bending were carried out,and finite element(FE) analysis were also conducted.A generalized yield line model considering the plastic development at both chord surface and chord sidewall was proposed to calculate the out-of-plane flexural capacity of the cross-type joints.Research results show that both two specimens are failed by tearing of the weld and the adjacent chord wall.The flexural capacity and energy dissipation capacity of the specimen with large BCHR are higher than those of the specimen with medium BCHR,while the ductility of the former is slightly lower.The simple yield line model remarkably underestimates the joints flexural capacity by 15% to 30%,and the generalized yield line model overestimates the joints capacity by 15% to 25%.While the average of the two models and the parameterized calculation equation(deduced from the generalized yield line model) can well predict the capacity,most errors are smaller than 10%.