基于重要杆件失效网架结构连续倒塌动力试验研究

Tests for dynamical progressive collapse of a grid structure based on key member failure

在网架结构模型中,基于杆件轴力与应变能变化响应的杆件重要性评估方法确定初始破坏杆件并引入失效装置,进行了基于杆件失效的结构连续性倒塌试验。在试验过程中,利用动态应变仪、拉线式位移和加速度传感器,获取网架结构模型因初始破坏引发的动态过程总的应变、位移和加速度时程曲线,揭示网架结构连续性倒塌的破坏过程及破坏机制。仿真分析和试验结果表明,支座之间及其相邻腹杆是网架结构关键杆件,其初始破坏失效后,会造成网架结构的连续性倒塌,在实际设计过程中要加强其构件承载力。

With a test model of a grid structure,tests were done for the progressive collapse of the structure based on member failure. The member importance evaluation method based on member axial force and strain energy change response was adopted to determine the initial failure member and a manually controlled failure apparatus was introduced.In tests,by using dynamic strain meters,guyed displacement and acceleration sensors,the time history curves of strain,displacement and acceleration of the model structure,in the dynamic process due to the initial failure were obtained. They revealed the collapse process and mechanism of the grid structure. The numerical simulation analysis and test results showed that the members between bearings and their adjacent members of the grid structure are key ones causing the progressive collapse of the grid structure after their initial failure; so,in the actual design,it is necessary to strengthen their load-bearing capacities.