空间管桁架结构连续倒塌试验研究

Experimental Study on the Progressive Collapse of Spatial Pipe Truss Structures

为揭示空间管桁架结构的连续倒塌破坏机理,对空间管桁架结构平面体系进行了连续倒塌动力试验研究。试验设计了杆件失效激发装置,模拟了桁架杆件的初始破坏,通过对剩余结构杆件应变和节点位移的测量,以考察剩余结构的动力响应。试验结果与数值模拟分析结果的比较说明,基于OpenSees程序的连续倒塌数值模拟分析能够较好地模拟初始局部破坏后剩余结构的动力响应。试验结果表明,下弦杆初始破坏后,结构发生转动铰机制下内力重分布,易引起较大的竖向变形及杆件内力变化,对结构的抗连续倒塌性能产生不利影响;且桁架弦杆对接焊缝的质量显著影响了结构的抗连续倒塌能力。

In order to study the progressive collapse failure of spatial pipe truss structures,aplanar model of spatial pipe truss structure is designed for the experimental study on progressive collapse.A failure excitation device is designed to simulate the initial failure of a truss member,and the rod strain and nodal displacement are measured to assess the dynamic response of the remaining structure.The comparison between experiment data and numerical analysis results indicates the numerical analysis using OpenSees is capable of simulating the dynamic response of remaining structures after initial local failure.Also,the experiment results show that after the initial failure of the bottom chord,the force redistribution of structure occurs with the rotating hinge mechanism,and this causes large vertical deformation and internal force variations in the members.The performance of anti-progressive collapse of structures is also affected.The quality of truss chord butt weld significantly influences the ability of structure to resist progressive collapse.