中文摘要：

研究层合板结构基于最终层失效准则的可靠性分析方法，在此坫础上，对复合材料层合板可靠性优化设计的方法和算法进行讨论。层合板作为一个系统考虑，其可靠性分析含以下几个步骤：（1）随机载荷和强度参数作为随机变量，利用一次二阶矩法（first order reliability method，FORM）分析单层板的失效概率。（2）假定失效概率最大的单层板首先破坏，然后通过修改刚度矩阵对结构进行再分析，得到剩余结构各单层板的失效概率，从而建立主要失效序列。（3）计算系统的可靠度。在确立复合材料基于最终层失效准则的可靠性分析方法的基础上，以系统可靠度指标最大为目标，研究层合板的可靠性优化问题。建立和发展基于最终层失效准则的复合材料层合板可靠性优化方法以及相应的算法，并对比讨论单变量和多变量优化设计问题。

英文摘要：

The system reliability of composite structures is analyzed fwst based on the last ply failure criterion （LPF）. Then the probabilistic optimum design problem is solved by genetic algorithm （GA）. The load and strength variables are considered as random variables and the first order reliability method （FORM） is used to compute the failure probability of plies. The laminate＇ s reliability is evaluated by utilizing the system reliability theory together with the significant failure sequences concept. The procedure includes： 1 ） Calculating the failure probability of plies by FORM; 2） Re-analyzing the laminates based on the stiffness reduction iule and lind the significant failure sequences; 3） Evaluating the system reliability by an approximate method. The genetic algorithm is used to analyze the probabilistic optimum design of laminates based on the LPF criterion. A method to effectively evaluate the safety of composites based on the LPF criterion is proposed and developed, and an adequate algorithm for solving the corresponding optimum design problem is established. The efficiency of multi-variables optimum design by GA is also studied.