型钢混凝土组合框架力学性能非线性分析

Nonlinear Analysis of Mechanical Property for Steel Reinforced Concrete Composite Frame Structure

在充分考虑混凝土损伤、材料非线性及单元类型的基础上,建立了由预应力(非预应力)型钢混凝土梁及角钢混凝土柱构成的型钢混凝土组合框架有限元模型,对其在水平荷载作用下的力学性能进行数值分析及试验对比验证。在此基础上,进一步研究了水平荷载作用下组合框架受力的全过程,并对影响此类框架力学性能的主要因素进行了参数敏感性分析。结果表明:组合框架在梁端和柱底部均出现塑性铰,能实现"强柱弱梁"的破坏机制;随着轴压比增大,水平荷载-位移曲线峰值荷载先增加后减小,峰值荷载对应的位移减小,延性降低;随着长细比增加,结构刚度降低,峰值荷载减小,延性增加。

A finite element model （FEM ） to simulate the composite frame structure composed of prestressed （non‐prestressed ） steel reinforced concrete beam and angle‐steel concrete column under horizontal loading was developed by considering concrete damage ,material nonlinearity and element type ,and the mechanical properties acquired from FEM were compared to test results . According to FEM ,the whole force process of composite frame structure under horizontal loading was studied ,and the primary factors affecting the mechanical property of the frame structure w ere analyzed . T he results show that the plastic hinges occur at the beam ends and column bottoms ,and the failure mechanism of “strong‐column and weak column” can be reached . Furthermore ,with increasing of the axial compression ratio ,the ultimate load of horizontal load‐displacement curves increases firstly and then decreases , corresponding to the displacements decrease and ductilities depress ;with increasing of slenderness ratio ,the stiffness of structure decreases ,the ultimate load reduces and the ductility gets better .