新型钢管混凝土节点的非线性有限元分析

提出一种新型钢管混凝土柱与钢筋混凝土梁的节点形式,在节点区中断外钢管,加设芯钢管,使钢筋混凝土梁中的钢筋在节点直通、节点与所连接构件的混凝土成为一体,解决梁的内力在节点传递的问题。为验证新型节点的合理性和可行性,在合理选择材料本构关系、破坏准则的基础上,采用通用有限元工具ANSYS,建立一个三维有限元模型,对芯钢管中柱节点模型的外钢管应力、芯钢管应力、混凝土应力、节点区裂缝进行了分析。结果表明,有限元分析结果与模型试验结果吻合良好,节点的承载力大于被其连接的构件的承载力,满足"强节点、弱构件"的抗震设计原则,证实了新型节点的合理性和可行性。

Nonlinear finite element analysis of new type joint in CFST (concrete filled steel tubular)

A new type of column-RC beam joint of concrete filled steel tubular (CFST) was created. The outer tubular column of CFST was disconnected in the joint zone, and the core steel tube was put in the joint zone. The steel bars in the RC beam are through in the joint, and make the concrete between the joint and the linked component to be one, which can solve the problems that the inner forces can be transferred reliably in the joint zone. Based on the appropriate material stress-strain relations and failure criterion, a 3-D nonlinear finite element method model was presented to analyze the mechanical properties of this new type concrete filled steel tubular joint-core steel tube joint of intermediate column with ANSYS. The results show that a good agreement between the experimental and analytical results, that it meets the seismic design principles of strong joint and weak element and that confirms the rationality and feasibility of the new joint.