基于泛灰数的结构疲劳寿命区间估计方法  

Estimation Approach of Structural Fatigue Life Based on Universal Grey Number

作　　者：陈小月[1] 文桂林[1] 刘杰[1] 卿启湘[1] CHEN Xiao - yue WEN Gui - lin LIU Jie QING Qi - xiang(Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, and Key Laboratory of Advanced Design and Simulation Techniques for Special Equipment, Ministry of Education, Hunan University, Changsha Hunan 410082, China)

机构地区：[1]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,湖南长沙410082

出　　处：《计算机仿真》2017年第4期245-249,共5页Computer Simulation

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)

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。Estimation of the structural fatigue life with uncertain parameters is usually of low precision when using interval parameters. Thus, a new method employing universal grey numbers to tackle the problem is proposed. First, uncertain design variables are represented as intervals without considering their specific distribution. Using universal grey number characters, we transform intervals into the equivalent universal grey numbers, and calculate the upper and lower bounds of the structural fatigue life. Two numerical examples indicate that the range of the structural fa- tigue life obtained by using the proposed method is narrower than those obtained by traditional interval methods. Moreover, they are almost the same to the results by using the advanced intercept method. Meanwhile, the Monte Carlo method is applied to verify the results of the proposed method. The proposed method can acquire a more precise result of fatigue life with less information. Furthermore, to some extent, it solves the problem that fatigue life parameter es- timation of actual engineering structure is usually too conservative. Thus, using our method to calculate the fatigue life of the engineering structure can save the design cost.

关 键 词：疲劳寿命估计 不确定性 区间分析 泛灰数 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]