低周反复荷载作用下桁架组合梁非线性分析

摘要

采用ansys有限元软件，结合钢桁架-混凝土组合梁的受力特点和试验时的真实状况，建立桁架组合梁空间有限元模型，将计算结果与试验数据对比以证明此模型的适用性和合理性。计算结果表明有限元模拟与试验结果吻合较好，验证了有限元模型以及编制APDL命令流的正确性。应用编制的命令流得到另外一根不同桁架形式的桁架组合梁在水平低周反复荷载作用下的响应，考察该结构的抗震耗能性能。由滞回曲线分析可得，桁架组合梁在水平低周反复荷载作用下刚度和强度退化不明显，说明该结构具有较好的耗能能力，变形能力强，承载力较高，且其正向承载力比反向承载力高，可为实际工程抗震设计提供参考。%In this paper,finite element software,ansys,was utilized to establish the space finite element model of the truss composite beam combined with the characteristics of the forces of the composite beam assembled by steel truss and concrete and the true state of the test,and then the results were compared with the experimental data to demonstrate the applicability and rationality of this model.The simulation calculations show good agree-ment with the experimental results,which verifies the correctness of the finite element model and APDL com-mand flow.Then APDL command flow was applied to get response of another different form of truss composite girder under horizontal low frequency cyclic load so as to examine the seismic energy performance of the struc-ture.By the hysteresis curve analysis available,stiffness and strength degradation of truss composite beam were not obvious under horizontal low cyclic load,indicating that the structure has a good energy dissipation capacity, strong deformation capacity,high bearing capacity,and its forward direction bearing capacity is higher than the reverse bearing capacity,which can provide practical reference for actual engineering seismic design.