非线性包装件加速度响应首次穿越问题分析

Acceleration response first passage failure probability analysis for a nonlinear package

研究非线性包装件在随机振动支座激励下加速度响应的首次穿越损坏概率的分析方法。将随机振动激励离散化表示在标准随机变量空间,构建求解包装件加速度响应首次穿越概率的分析方法。对于非线性系统,应用模型修正因子法构建了系统修正理想化分析模型,用于近似估计非线性系统设计点,由于应用模型修正因子法估计的可靠度指标不小于真实非线性系统可靠度指标,应用最小化可靠度指标求得理想化模型的参数,可准确求得非线性系统设计点。应用一阶可靠性方法分析了非线性包装件加速度首次穿越损坏的概率。实例分析表明,所构建的首次穿越损坏概率分析方法具有良好的准确性,对于包装件振动可靠度分析和优化包装设计具有重要意义。

An acceleration response first passage failure probability estimation method for nonlinear package excited by random base excitation was presented in this paper.The random vibration excitation was presented in normal random variable space,an analytical method was used to obtain the first passage probability.The design point is essential information for the failure probability analysis.The model correction factor method(MCFM)was used to develop an approach to approximately obtain the design point,since the MCFM always provide upper bound to the reliability index,the parameters of idealized system were determined by minimizing its reliability index.The acceleration response first passage failure probability can be estimated by the first order reliability method.An example was presented in this paper to demonstrate the accuracy of the method.The method in paper is important for the vibration reliability analysis and design optimization of the package.