索的破断涉及到强烈的几何非线性,传统的有限元方法很难准确模拟和跟踪其失效过程,利用基于MAT-LAB语言的自编向量式有限元程序对弦支穹顶的斜索和环索失效全过程进行了跟踪模拟分析,得到了弦支穹顶断索后位移和内力的动力响应曲线.结果表明:利用向量式有限元能够准确地进行断索全过程分析,任一环索断裂后将导致整圈索杆体系失效,环索断裂对于结构位移及内力影响较斜索断裂时更大.断索将同时导致最终平衡态支座反力的大幅增加,在预应力结构设计时应予以足够的重视.
The cable rupture always relates to strong geometrical nonlinearity, so the process is difficult to simulate and trace. The failure analysis of suspen-dome including ridge cable and hoop cable rupture was studied by the vector form intrinsic finite element (VFIFE) program based on MATLAB language. The displacement and internal force curves were obtained after the suspen-dome went to invalid. Numerical re- sults show that VFIFE is accurate in case of analyzing the whole cable rupture process. Any hoop cable rupture would result in the failure of the whole circle cable-strut assembly. The hoop cable has more influ- ence on the displacement and internal force of the structure than the ridge cable. The last reaction force will increase seriously because of the cable rupture, so more attentions should be put into the structure bearing design involving prestress.