杆系结构系统失效模式识别的几何法及其应用

The Geometric Method of Failure Mode Identification of Frames and Its Application

在结构可靠性分析中,由于外载、材料性能参数等的随机性,在所有可能的失效模式中,必有少数几个失效模式其出现概率比其他失效模式要大得多,因此求取这为数不多的临界失效模式就是结构系统可靠性分析中一个主要课题.本文提出了求取杆系结构系统失效模式(即机构)的几何法.它是从几何方程出发,求得一机构,然后在此机构的基础上经过简单的矩阵相加.相乘就可得到其他机构.同时采用比例加载乘子λ这一物理意义明潦的参数来作为判别是否为临界机构的准则,效果很好.算例表明了此法的可行性,有效性.

In structaral reliability analysis, due to the randomness of the applied load and material characteristic parameters, there must exist several mechanisms whose failure probabilities are much larger than any others, of all the potential failure modes. It is the key subject for reliability analysis of structural system' s to identify these critical mechanisms. The geometric method proposed in this paper gen- erates a mechanism by the use of the struturol geometry equotion at first, then bosed on this generated mechanism we can find other mechanisms only by simple addition and multiplication of matrix. Meanwhile, the proportionally loading multiplier λ with its clear physicol meoning is used as a criterion of identifying the critical mechanisms. The results show that the method is very feosible and quite effective.