引入初始破坏的桁梁结构倒塌试验研究

Experimental Study on Beam-truss Structure Model by Introducing Incipient Failure in Collapse

对空间桁梁结构模型进行了倒塌试验.研制了连续性倒塌试验中人工控制的初始破坏引入装置.利用动态应变数据采集系统以及数字图像处理技术获取初始破坏引发的动力过程中的应变和位移,数据分析可得到结构破坏过程的持续时间,测点的应变时程曲线,观测点的位移时程曲线,揭示了破坏过程及破坏机制.结果表明:构件承载力富余程度的高低及空间效应是结构抗倒塌重要的冗余度.采用理论分析和数值分析对结构的破坏过程进行了模拟.

Experiments on structural progressive collapse were carried out on truss-beam in a three dimensional system model.A manually controlled apparatus inducing initial member failure was developed,which could be easily installed as part of structural members subjected axial forces.By using non-contact digital image processing technique and high frequency strain acquisition system,the displacements and strains during the dynamic process after initial member failure could be obtained.The duration of collapse process,displacement and strain history at the measuring spots were analyzed to reveal the collapse mechanism.The results show that the margin of loading capacity of members over their inner forces induced by vertical loads and the interaction of structural components in the three dimensional system provide main redundancy against progressive collapse.Simple model analysis and non-linear dynamic numerical simulation were also performed to explain the behavior of failure process.