纤维复合材料的可靠性优化研究

采用遗传算法分析有初始缺陷的层合板的可靠性优化问题.初始缺陷、强度参数为随机变量,采用一阶矩法分析单元层的可靠性,每个单层板考虑基体破坏和纤维断裂两种失效模式,系统失效概率的计算基于最终层失效理论.以纤维方向角和层合板厚度为设计变量,系统可靠度最小为目标,采用遗传算法计算优化问题.数值算例说明方法的有效性,分析不同失效理论时的最优解.

RELIABILITY-BASED OPTIMUM STUDY ON FIBER REINFORCED PLASTICS

A probabilistic optimum problem of composite laminates with initial imperfection using genetic algorithms is analyzed. The initial imperfection, the strength parameters are considered as random variables, matrix cracking and fiber breaking are defined as the two basic failure modes. Ply-level failure probability is evaluated by the first order reliability method and system reliability is computed based on the last-ply failure criterion. A structural optimization problem is solved with the fiber orientation and the lamina thickness as the design variables, the system reliability as the objective, and which is performed by genetic algorithms. A numerical example is presented to demonstrate the methodology proposed and to contrast the optimal solutions.