基于子结构等效刚度修正的抗震混合试验方法研究

Research on hybrid seismic test of steel frames based on equivalent stiffness modification of substructure

为了研究试验子结构等效刚度对结构抗震混合试验结果的影响,以结构固有频率设计为基础,并根据振动台的尺寸和承载能力要求设计两榀三层三跨的钢框架模型做地震模拟振动台试验;根据结构的对称特性选取框架底层1/4及1/2结构为试验子结构并利用结构变形协调原理对试验子结构边界自由度进行缩减,设计了双通道作动器协同控制加载技术对试验子结构边界条件进行模拟,最后对所设计的三层钢框架模型进行混合试验,混合试验结果与振动台试验吻合较好,这表明在结构振动台抗震性能试验受限于台面尺寸和承重等因素时,基于子结构等效刚度的混合试验方法可为结构抗震性能分析提供一种有效的途径。

In order to study the effect of the equivalent stiffness of the experimental substructure on the results of the seismic hybrid simulation,according to the size and bearing capacity of the shaking table,a steel frame model with two pairs,three floors and three spans is designed to do shaking table tests of earthquake simulation based on the natural frequency of the structure and the bearing capacity of the shaking table for shaking table test.According to the symmetry of the structure,the 1/4 and 1/2 structures of the bottom frame are selected as sub-structures,and the boundary degrees of freedom of the sub-structure are reduced based on the principle of structural deformation coordination.A dual-channel actuator technology is designed to simulate the boundary conditions of the test substructure,and then the hybrid simulation test of the designed three-story steel frame model is carried out.The results are consistent with the shaking table test,which indicates that when the seismic performance test of structural shaking table is influenced by such factors as table size and load-bearing,the hybrid simulation based on the equivalent stiffness of the substructure can provide effective way for the structure seismic analysis.