【摘要】 基于不确定参数的凸集合描述,研究了多学科耦合系统的非概率可靠性分析问题。由于多学科系统分析的迭代性质,直接求解非概率可靠性模型将包含两个嵌套的循环,计算量较大。本文根据“同时分析和设计(SAND)”的思想,建立了求解非概率可靠性指标的SAND模型,使其求解仅包含一个单级循环(优化过程),较大程度上减少了计算量。通过一个典型的多学科分析算例比较了两种方法的计算结果和计算量,表明本算法是合理有效的,同时比较了概率可靠性与非概率可靠性指标的异同。更多还原

【Abstract】 In this paper, the reliability analysis problem of multidisciplinary systems is investigated by using non-probabilistic approach, that is, convex set of uncertainty. This method is a rational way to deal with uncertainties when available information is insufficient to warrant probabilistic analysis. The main aim of this paper is to develop computationally efficient techniques to calculate the non-probabilistic reliability index for multidisciplinary systems. Because of the interactions among various disciplines, the execution of the system level analysis is iterative by nature. Thus the all-in-one reliability analysis method requires a double-loop procedure and therefore is generally very time-consuming. To improve the computing efficiency, a new formulation is constructed according to the idea of SAND(Simultaneous Analysis and Design). In this formulation, the system level analysis is avoided and the interdisciplinary compatibility will be achieved progressively. As a result, only a single loop is required and all the analysis can be conducted concurrently at the individual discipline-level. Both methods are validated and compared in application to an electronic packaging problem. The calculated reliability index values are also compared with the safety frequencies obtained by Monte-Carlo simulation.更多还原