单向相关下的机械零件动态可靠性分析

摘要

For such a condition of the correlation existing between load and strength,the application of the traditional stress-strength interference model has some limitations.For evaluating the dynamic reliability of the parts under the unidirectional correlation of the stress and strength,the Gamma process is adopted to describe the random loading and deduce the strength degradation model with the strength lowering with the loading based on the classic Miner cumulative damage theory.Moreover,the model of the parts dynamic reliability has been established on the basis of the stress-strength interference model.Finally,numerical examples are used to verify the effectiveness of the test model,with the results showing that this model can be effectively used to assess the dynamic reliability of the parts in case of unidirectional correlation.%对于载荷与强度存在相关性的情形,应用传统的应力-强度干涉模型具有一定的局限性.为评估零件在应力与强度单向相关下的动态可靠度,利用Gamma过程来描述随机载荷作用,基于经典的Miner累积损伤理论,推导随着载荷作用而产生的强度不断降低的强度退化模型.结合应力-强度干涉模型,进而建立零件的动态可靠度模型.最后通过算例验证模型的有效性,结果表明,该模型能够有效用于零件在单向相关下的动态可靠性评估.