强柱弱梁型多层钢结构的动力损伤机理分析

Dynamic Damage Mechanism Analysis of Strong Column-Weak Beam in Multi-story Steel Structures

基于钢结构的动力损伤机理不明,为进一步研究强柱弱梁型多层钢结构损伤机理,以柱脚形式、强柱系数即α的不同定义方式及结构首层剪重比为主要研究参量,设计6个强柱弱梁型多层钢结构模型;对模型进行弹塑性分析,研究层间位移响应、柱梁塑性变形能量总合值的各层分布、首层柱梁端塑性变形能量及滞回曲线等。计算表明:首层剪重比的增大(从0.25增大至0.45),在设防烈度地震下递减结构层间位移响应,而罕遇地震下没有递减结构层间位移响应;各层柱梁的塑性变形能量最大值的总合值,首层值偏大;其中,首层塑性能量,柱脚刚接模型集中于柱底端,柱脚铰接模型主要集中在梁端;强柱系数按节点设计的模型,塑性变形能量主要向各层梁端分布;罕遇地震下柱梁需求性能远小于焊接连接的柱梁节点具备的持有性能。

The mechanism of dynamic damage based on steel structure is unknown,in order to analyze the damage mechanism of strong column-weak beam in multi-story steel structures,six numerical simulation models were designed with the type of column base,the design method of strong column coefficient and the first story shear-weight ratio as main research parameters.Elastic-plastic analyses for six models were carried out to test the inter-story response,story distribution of the total energy of plastic deformation of beams and columns,plastic deformation energy of first story beam and column ends,and hysteresis curve.The results show that:with the increase of the first story shear-weight ratio(from 0.25 to 0.45),the inter-story drift response of the structure decreases under fortification intensity earthquake action,but the response change is not obvious under rare earthquake action;for the total value of the maximum plastic deformation of each story beam and column ends,the value of the first story is relatively large;especially,the deformation energy of the first story concentrates on the column ends for rigid connection models,and on the beam ends for pinned connection models;for the models with the strong column coefficient designed by joints,the plastic deformation energy mainly distributes to beam ends of each story;furthermore,the required performance of beam-column joints under rare earthquake is far less than the existing performance of beam-column joints with welded connection.