复合随机振动系统的动力可靠性矩独立重要性测度及态相关参数解法  

Moment-independent importance measure of dynamic reliability for double random vibration systems and its state dependent parameter solution

作　　者：张屹尚[1] 刘永寿[1] 赵彬[1] 翟红波[1] 

机构地区：[1]西北工业大学工程力学系飞行器可靠性工程研究所,西安710129

出　　处：《振动与冲击》2014年第16期109-114,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51205312);航空科学基金(2011ZA53014);航天支撑基金(NBXW0001);西北工业大学基础研究基金(JC201114)资助项目

摘　　要：针对激励与结构参数同时存在不确定性的复合随机振动系统,由随机结构无条件动力可靠度表达式出发,利用条件概率密度函数解析变换给出衡量基本随机变量对动力可靠性影响的矩独立重要性测度指标。该指标可表征不确定性随机变量对动力可靠度响应量分布的平均影响程度,可全面反映随机变量对响应分布影响。基于状态依存参数模型,提出求解矩独立重要性测度指标的态相关参数(SDP)法。利用算例分析结构动力可靠性参数的矩独立重要性测度,并与直接Monte-Carlo法对比。所提方法可在保证计算精度同时大幅度提高计算效率,适用于分析复合随机振动系统非线性可靠性响应。A moment-independent importance measure index of dynamic reliability for double random vibration systems,in which the randomness of structural parameters and excitation was taken into account,was introduced to analyze the effect of input variables on dynamic reliability. Based on the expressions of unconditional dynamic reliability and conditional probability density function（ PDF）,the importance measure index was numerically obtained. The index can effectively describe the mean effect of the PDF on dynamic reliability from the distribution density of the basic variable. Then,on the basis of the state dependent parameter（ SDP） model,the SDP method was established to estimate the defined moment-independent importance measure index. Additionally,two examples were given to illustrate the advantages of the presented method. Comparing with the direct Monte Carlo method,the results show that the established solution can considerably improve computational efficiency with acceptable precision and be suitable for analyzing nonlinear dynamic reliability responses of double random vibration systems.

关 键 词：复合随机振动 矩独立 重要性测度 态相关参数法 动力可靠性 

分 类 号：TB114.3[理学—概率论与数理统计]