劲性支撑穹顶结构是一种新型的索结构,断索(杆)分析对结构破坏机理和倒塌性能研究有十分重要的意义。运用瞬态动力学的Newmark时间积分法对单根索(杆)断裂后结构的力学性能进行分析,提出了响应变化率和动力响应系数,运用其评价各类索(杆)破断对结构的影响程度。根据局部断索(杆)是否引起其他索杆的强度破坏和过大位移将杆件分为全局敏感性构件、局部敏感性构件和不敏感性构件。提出了一种杆件重要性系数,表征杆件的重要性并对其重要性排序。研究表明:内外环杆、外斜杆和外撑杆破断结构发生连续倒塌,其为全局敏感性构件;外脊索、中脊索、内脊索、中斜杆、内斜杆和内撑杆破断对其附近的构件影响较大,为局部敏感性构件;外环杆的杆件重要性排在首位,内脊索排在末位。
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 Newrnark 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 com- ponent.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.