针对影响工程系统的随机因素通常服从正态分布的情况,提出一种基于改进的Box-Behnken试验设计法的可靠性灵敏度分析方法.根据工程系统特点,采用含有交互效应的二阶响应面模型来描述因素和响应之间的非线性关系;基于正交性和旋转性原则,在Box-Behnken二阶设计的基础上添加轴点,使试验设计的样本点符合随机因素分布特征;从而,拟合响应面函数,建立系统极限状态方程,进行可靠性灵敏度分析.最后,通过车辆系统平顺性可靠性灵敏度分析实例,说明了该方法在分析随机系统方面的优越性;Monte Carlo仿真实验结果表明,该方法可行有效,计算精度高,可以为工程实际提供指导.
Random factors affecting engineering system usually obey normal distribution,a Box-Behnken experiment design method based on improved reliability sensitivity analysis method is proposed.According to the characteristics of the engineering system,the contain interactive effect of the second order response surface model is used to describe the nonlinear relationship between factors and response.Based on the orthogonality and rotating sex principle,adding axis point in the Box-Behnken; on the basis of the second order design,it makes that the test design conforms to the characteristics of random factors distribution of sample points.Thus,fitting the response surface function,establish the system of limit state equation,the reliability sensitivity analysis.Finally,through an example of vehicle suspension system reliability sensitivity analysis,it is shown that the method is based on the analysis of the superiority of the stochastic system.Monte Carlo simulation experiment results show that this method is feasible and effective; the calculation accuracy is high,so as to provide guidance for the engineering practice.