基于区间不确定性的多学科可靠性设计

针对随机可靠性设计和多学科设计直接结合中存在的随机可靠性无法解决不确定性信息量较少及直接结合的嵌套结构计算效率较低的问题,采用区间描述有限信息的不确定性,以非概率可靠性指标衡量多学科系统的可靠性,建立了基于区间不确定性的多学科可靠性设计模型.同时,为了提高计算效率,采用性能测量法来减少可靠性分析的计算量,并引入序列优化与可靠性评估方法将三层嵌套的多学科可靠性设计结构解耦为顺序执行的确定性多学科设计优化和多学科可靠性分析过程,降低了计算复杂性.通过一个算例验证了该方法的可行性和有效性.结果表明,相比多学科可行法,单学科可行法的计算效率较高.

Optimization of Multidisciplinary Reliability Design Based on Interval Uncertainty

Abstract： Aimed at the problem resulted from the direct integration of random reliability-based design and multidisciplinary design optimization that the random reliability method cannot solve the problem with limited uncertainty information and the nested structure of direct integration has low computational efficiency, the model of interval uncertainty based multidisciplinary reliability design was presented, in which the uncertainty with limited information was described with interval variable and the reliability of multidisciplinary system was measured with non-probabilistic reliability index. Moreover, to improve the efficiency, the performance measurement approach was applied to reduce the computational cost of the reliability analysis and the sequential optimization and reliability assessment method were applied to simplify the computation process through decoupling the 3-layer nested structure into sequential deterministic multidisciplinary design optimization and multidisciplinary reliability analysis. A numerical example was used to test the feasibility and effectiveness of the method. The results show that IDF has higher efficiency than MDF.