基于泛灰数的结构疲劳寿命区间估计方法

发布时间：2018-10-26 15:09

【摘要】：针对利用区间算法求解含有不确定性参数结构的疲劳寿命值精度低问题,提出一种泛灰求解方法。泛灰数运算不仅可以有效处理结构不确定参数,且能解决区间运算扩张问题。首先将不确定性设计变量用区间数来表征,不考虑变量的具体分布情况;其次利用泛灰数特性,将区间变量转化为泛灰数,利用等效泛灰数计算结构疲劳寿命上下界;最后通过两个数值算例,求得的结构疲劳寿命范围比传统区间算法得到的范围更小,且与改进的截断法的结果相近,同时还利用Monte Carlo方法验证了方法的有效性。泛灰方法利用较少的信息量得到较精确的疲劳寿命估计结果,一定程度上解决了工程实际结构参数疲劳寿命估计过于保守问题,节约了设计成本。
[Abstract]:In order to solve the problem of low precision of fatigue life value with uncertain parameter structure by using interval algorithm, a universal grey method is proposed. Universal grey operations can not only deal with structural uncertainties but also solve the extension problem of interval operations. First, the uncertain design variables are represented by interval numbers without considering the specific distribution of variables; secondly, the interval variables are transformed into universal grey numbers by using the characteristics of pan-grey numbers, and the upper and lower bounds of fatigue life of structures are calculated by using equivalent universal grey numbers. Finally, two numerical examples show that the range of fatigue life of the structure is smaller than that of the traditional interval method, and is close to the result of the improved truncation method. The validity of the method is also verified by using the Monte Carlo method. Using less information, the pan-grey method can get more accurate results of fatigue life estimation, which to some extent solves the problem that the fatigue life estimation of engineering structure parameters is too conservative and saves the design cost.
【作者单位】：湖南大学汽车车身先进设计制造国家重点实验室和特种装备先进设计与仿真教育部重点实验;
【基金】：高等学校博士学科点科研基金资助课题(20120161130001) 国家杰出青年科学基金(11225212)
【分类号】：TB114.3

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