翼缘削弱的型钢混凝土框架试验与有限元分析

Experimental Study and Finite Element Analysis of SRC Frame with Dog-bone Type Reduced Beam Sections

通过对一榀两跨三层型钢混凝土框架模型的低周反复荷载试验,研究了翼缘狗骨式削弱的型钢混凝土框架的抗震性能。框架按"强柱弱梁"的原则设计,且对节点核心区附近梁端工字形型钢的上、下翼缘采取狗骨式削弱,并适当增加了梁端根部到型钢翼缘最大削弱部位纵向钢筋的配筋量。试验结果表明:框架的变形能力、承载能力、延性、耗能能力等受力性能均满足延性框架的抗震要求;这种构造措施能将塑性铰从梁端根部转移到翼缘削弱部位从而有利于型钢混凝土框架形成梁铰耗能机构,增强其耗能能力。采用ANSYS参数化程序设计语言(AP-DL)编制了命令流,对模型框架在低周反复荷载作用下的抗震性能进行了非线性有限元分析。计算结果与模型试验结果吻合较好,验证了基于分离模量理论计算的翼缘削弱的型钢混凝土框架结构全过程分析方法的可行性。

The seismic SRC frame with dog-bone type reduced beam sections has been investigated based on the experiment and analysis of a 2 bays,3-stories model of SRC frame under cyclic loading.The frame designed as ＂strong column-weak beam＂ is treated with dog-bone style weakening on the upper and below flanges of the H-type steel at the beam end near the joint core,and the ratio of reinforcement which distribute from the root of beam end to the maximum weakened flanges of the H-type steel is increased.The test results show that deformation capacity,bearing capacity,ductility and energy dissipation of the frame may meet the requirement for seismic design of ductile frames and the constitution may not only transfer a plastic hinge from the root of beam end to the reduced beam section,but also help the frame form the energy dissipation mechanism with plastic hinges at beam ends so as to increase the integral energy dissipation capability of the frame.A command stream is edited with the ANSYS Parametric Design Language（APDL）,and the nonlinear finite element analysis on the seismic behavior of the model frame under lateral cyclic loads is completed.The calculated results are much coincided with the tested results,which further proves the rationality of the design method of the SRC frames based on the separated modulus theory of SRC.