复合材料层合板的率模可靠度研究

传统的结构可靠性分析是基于二值状态假设的,即结构要么处于失效状态,要么处于安全状态,但在许多工程实际中,在失效和安全之间有一系列中间状态,因此判断结构是否失效,引用模糊状态的概念更为合理.该文将失效(或安全)的模糊状态假设引入到复合材料层合板的可靠度分析和计算中,建立了复合材料层合板的率模可靠度模型和相应的计算模型.在该模型中,考虑了单层复合材料强度指标的随机性,以及极限状态的模糊性.由层合板结构可靠性分析的具体算例,说明了该文模型和计算方法的合理性及有效性.同时,对参数的影响也进行了分析和讨论.结果表明,强度参数的均值以及失效准则的选取对可靠度有较大的影响.

A RELIABILITY MODEL FOR LAMINATED COMPOSITES BASED ON A FUZZY STATE ASSUMPTION

In the conventional reliability theory, a binary state assumption that a system is either in function or in failure state is used. But in practice, there may exist a series of sates between the two limit states, and thus the fuzzy state assumption should be used to replace the binary state assumption. In this paper, a fuzzy reliability model of composite materials is established by introducing a fuzzy assumption for the structure state together with the probabilistic assumption for strength parameters of the material. We call the reliability from the model the profust reliability. Examples are given to illustrate the validity and efficiency of the profust model proposed. The influences of strength parameters and failure criteria on the assessed reliability are discussed. By using the model and the computation method developed in this paper, we can evaluate the reliability of composites more rationally and synthetically.