面向体系非线性分析的钢管混凝土柱-组合梁节点多尺度高效数值模型

Multi-scale efficient numerical model of concrete filled steel tube-composite beam joint for nonlinear analysis of structural systems

基于组合结构非线性分析软件COMPONA-MARC V1.2,提出面向体系非线性分析的钢管混凝土柱-组合梁节点多尺度高效数值模型,该模型能准确反映梁端、柱端以及节点域的耗能特征。首先建立模型的总体框架,采用较为简洁的多尺度连接方案,并从节点传力机理的角度证明其合理性。其次,在单向地震作用下楼板空间组合效应模型的基础上,通过对极限正弯矩有效宽度进行折减,提出双向地震作用下考虑楼板空间组合效应的组合梁纤维模型。随后,选取基于裂缝带模型的组合节点域混凝土单轴受拉软化模量计算公式,重点讨论平均裂缝间距这一关键参数的取值方法,给出与开裂应变相关的剪力传递系数计算方法的建议。最后采用本模型对一系列平面和空间组合节点的抗震性能试验进行模拟,充分证明本模型的准确性与合理性。

A multi-scale efficient numerical model of concrete filled steel tube-composite beam joint for nonlinear analysis of structural systems is proposed by the nonlinear analysis FE package for composite structures COMPONAMARC V1. 2. This model can accurately reflect the energy dissipation characteristics at beam ends,column ends and joint cores. The overall framework of the model is first developed. A multi-scale tie scheme is selected and verified from the standpoint of the joint force transferring mechanism. Then,a fiber model of composite beam considering the slab spatial composite effect under bi-directional earthquake is proposed based on the slab spatial composite effect model under unidirectional earthquake by reducing the effective flange width on the equivalence of ultimate positive moment.Furthermore,the formula for the uniaxial tensile softening modulus of the composite joint core concrete based on the crack band model is selected. The determination of the average crack spacing,which is one of the most critical parameters for calculating the uniaxial tensile softening modulus,is concentrated on. The formula for calculating the shear retention factor related to the cracking strain is also proposed. Finally,the accuracy and rationality of the proposed model are extensively verified by the cyclic loading test results of a series of plane and spatial composite joints.