改进型节点钢框架整体模型的抗震性能对比分析

Seismic performance comparison of steel frames with improved beam-column connections

针对钢框架梁柱加宽型节点、削弱型节点和加宽-削弱型节点,在已经完成了三种改进型梁柱节点试验与有限元分析的基础上,采用ABAQUS有限元软件建立了8层三种改进型节点框架和普通刚接框架模型,对其进行模态和8度罕遇地震作用下的动力时程分析,并详细对比分析四种钢框架的抗震性能。分析结果表明:与刚接框架相比,三种改进型节点框架在8度罕遇地震下实现了节点塑性铰外移,保护了梁端焊缝。与节点削弱型框架相比,节点加宽-削弱型框架有效的控制了结构的层间位移角;与节点加宽型框架相比,节点加宽-削弱型框架对结构基底剪力影响不大,柱脚和节点域塑性应变小于节点加宽型框架,因此具有更为可靠的抗震性能。

Based on the experiment and finite element analyses on some improved connections,including the reduced beam flange connection,widened beam flange connection and widened-reduced beam flange connection,the finite element models of three steel frames with these connections as well as the rigid frame were built by using ABAQUS software. The modal analysis and the dynamic time-history analysis of the steel frames were carried out to compare their seismic behaviors with that of the rigid frame. The analysis results indicate that in the three improved steel frames,the plastic hinge could be shifted away from the panel zone to protect the welded seam at the beam end under a 8-degree rare earthquake. Compared with the reduced-beam flange steel frame,the widened-reduced beam flange steel frame can control more effectively the story drift. Compared with the widened-beam flange steel frame,the widened-reduced beam flange steel frame has less influence on the base shear force and leads to the smaller development of plastic strain in the column base and panel zone. Therefore,the widened-reduced beam flange steel frame has better seismic behavior.