钢管混凝土压弯构件的截面瞬时刚度分析

Calculation of Instantaneous Stiffness of Concrete Filled Steel Tubular Components

摘要: 在钢–混凝土组合结构体系的静力、动力弹塑性分析中，钢管混凝土构件一般都离散为梁单元，单元截面刚度是计算过程中重要的力学性能参数，可以描述塑性变形沿截面高度的扩展程度，且随内力呈非线性变化。因而在分级加载过程中要反复计算截面的瞬时刚度，其计算的精度和效率直接影响结构体系的分析结果。本文基于层纤维模型，给出钢管混凝土压弯构件截面瞬时刚度的迭代算法。利用C语言编制了相应的通用程序，通过典型算例分析了钢管混凝土截面的非线性性能，证明算法的有效性。本文为复杂截面刚度计算提供了新算法。

Abstract: In the static and dynamic elastoplastic analysis of steel-concrete composite structure, con-crete-filled steel tubular components are generally separated into beam elements. The stiffness of the unit is an important mechanical parameter during the process of calculation. It can describe the degree of extension of plastic deformation along the depth of section and nonlinear variation of internal force. Therefore, it is necessary to calculate repeatedly the instantaneous stiffness of the section under the step loading. The accuracy of calculation and efficiency influences the analysis results of structure system. The paper bases on distributed plasticity model, gives the iterative algorithm of instantaneous stiffness of concrete filled steel tubular components, uses VC compile general program, and analyzes nonlinear performance of the section of concrete-filled steel tube by typical examples. This paper provides a new algorithm for calculation of complex section stiffness.