Abstract:Rigid bracing dome is a new type of cable structure and broken cables (rods) analysis is very important for the failure mechanism and collapse performance of vcts structure.The structural mechanical properties of the broken cable (or rod) are analyzed by the Newmark time integration method of the transient dynamics.The response rate and dynamic magnification factor are given,and the influence degree of the broken cable (or rod) on the structure is analyzed by these parameters.The members are divided into global sensitivity components,local sensitivity components and insensitive components through the cable (or rod) breaking caused by the destruction of strength and excessive displacement of the other cables.The importance coefficient of the member is defined,and component importance is analyzed.Research shows that because the inner and outer ring rod,outer oblique rod or outer support rod is break,the structure will undergo a progressive collapse and are global sensitivity component.Lateral upper cable,middle upper cable,internal upper cable,middle oblique rod,internal oblique rod and internal support rod are locally sensitive components.The component importance of outer ring rod is the first,and internal upper cable is the last.