组合截面轴压短柱的非线性有限元分析

圆管或方管内填充另一种工程材料构成的组合截面构件（如钢管混凝土）在工程结构中得到了广泛的应用。本文借助商用有限元分析软件ABAQUS，利用软件子程序接口，引入应力场变量，来考虑两种材料本构关系的非线性以及受力过程中Poisson比、模量的变化等因素，建立了组合截面短柱在轴心压力作用下的非线性有限元计算模型。并通过数值算例，计算了组合截面短柱在轴心压力作用下两种材料共同受力工作的荷载－变形曲线，与试验结果基本符合，同时得到了管材对核心材料约束的变化规律。

Nonlinear Finite Element Analysis of Axially Loaded Combined Section Short Columns

Combined section columns which are made of a circular or a square tube filled with another material are used widely in engineering structures, such as concrete filled tube. Taking into account the effect of material nonlinear constitutive relation and the variation of Poisson's ratio under loading, the finite element models for axially loaded combined section columns were proposed. With numerical examples, the load deformation curves of the axially loaded combined section short columns were obtained, which coincide well with experimental data. The constraint of the tube to the core material and the factors which have influence on the load bearing capacity of the combined columns were analyzed.