一种结构概率-模糊-凸集混合可靠性新方法

发布时间：2018-06-12 13:39

本文选题：结构可靠性 + 随机变量　；参考：《应用力学学报》2017年02期

【摘要】：建立了结构同时含有概率、模糊、凸集变量时的可靠性分析模型。首先对模糊变量取一截集水平α,得到与模糊变量向量相对应的区间向量,将问题化为仅含有随机变量和凸集变量的混合可靠性问题。其次根据随机和凸集两类变量的混合可靠性方法,得到截集水平α下,以凸集变量为自变量的可靠度的均值,即截集水平α下的结构混合可靠度值。然后,将结构混合可靠度在截集水平区间[0,1]内进行积分,得到三类变量混合的结构总体可靠度。对所定义可靠度指标的物理意义进行了解释,并以某典型功能函数为例,进行了公式推导。最后,给出了算例分析,方法的可行性及合理性得到了验证。算例还表明,当忽略模糊变量的模糊性质,或改变凸集变量的数学型式,都会引起可靠度结果的失真,因此在工程实际中,必须全面客观地处理各类不确定性变量,才能得到正确可信的可靠性分析结论。
[Abstract]:The reliability analysis model of the structure with probabilistic, fuzzy and convex set variables is established. Firstly, the interval vector corresponding to the fuzzy variable vector is obtained by taking a cut set level 伪 for the fuzzy variable, and the problem is transformed into a mixed reliability problem with only random variables and convex set variables. Secondly, according to the mixed reliability method of random and convex set variables, the mean value of the reliability of convex set variables as independent variables, i.e. the structural mixed reliability value at truncated set level 伪, is obtained. Then, the structural mixed reliability is integrated in the horizontal interval of the cut set, and the structural total reliability of three kinds of mixed variables is obtained. The physical meaning of the defined reliability index is explained, and the formula is deduced by taking a typical functional function as an example. Finally, an example is given and the feasibility and rationality of the method are verified. The numerical examples also show that when the fuzzy properties of fuzzy variables are ignored or the mathematical forms of convex set variables are changed, the reliability results will be distorted. Therefore, in engineering practice, all kinds of uncertain variables must be dealt with comprehensively and objectively. In order to get the correct and credible conclusion of reliability analysis.
【作者单位】：海军工程大学舰船高温结构复合材料研究室;海军工程大学动力工程学院;
【基金】：国家自然科学基金(51509254) 海军工程大学青年基金(HGDQNJJ13013;HGDQNEQJJ15009)
【分类号】：TB114.3

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