中文摘要：

针对桁架结构薄弱环节和关键构件的研究，分别以传递函数阵的H。范数及杆件应变能的相对值作为衡量结构整体性能和初始干扰的参数，给出了结构易损性的量化指标，通过桁架结构算例，验证了易损性评价指标的有效性和可行性．在此基础上，基于破坏场景的定义，采用最易破坏场景确定各构件的重要性系数；由最大破坏场景来确定结构破坏的最短路径，即关键路径；用最易损场景寻找结构中存在的易损路径，即薄弱环节．结合有限元软件ANSYs和数学T具MATLAB计算易损性指标，根据其大小将结构易损性进行等级划分，由倒塌和高度易损等级确定了结构的关键路径和薄弱环节，从而为桁架结构的破坏识别提供了一种新的量化评价标准．

英文摘要：

To investigate the weak link and key components of truss structures, this work took the H2 norm of the transfer function matrices as the structural performance measurement and the relative value of the strain energy as the measurement of the initial disturbance, respectively, then gave a quantitative de- scription of the structural vulnerability with the two parameters. A vulnerability analysis of a truss struc- ture was presented to validate the effectiveness and feasibility. According to the definition of failure sce- narios, the element important coefficient was identified with the minimum failure scenarios; and the shor- test failure path of the structure, also namely the key path, was identified with the maximum failure sce- narios; and the vulnerable path, also namely the weakness of the structure, was identified with the most vulnerable failure scenarios. By employing finite element software ANSYS and mathematical tool MAT LAB, the vulnerability index was calculate＇d, based on which, the failure scenarios were ranked, then the key path and the congenital weakness could be obtained by searching the collapse and highly vulnerable rank. This method provides a new evaluation standard to recognize the failure of truss structures.