The piston of high power engine worked in the environments of periodic explosion pressure,piston pin reaction,high temperature and cyclic thermal.In order to study the creep-fatigue failure frequently appeared on the piston,the influence law of material and high temperature were studied by experiment and numerical simulation.A reliability design analysis method based on fault physics was put forward.Failure mechanism was treated as a unit.The damage models of creep,fatigue and their interaction were established respectively.The creep-fatigue reliability model of piston was established based on the linear damage accumulation method.The reliability,sensitivity and reliable life of piston were analyzed and calculated.And calculation method was compared with Monte Carlo method.Calculation results are Similar,but amount of calculation is obviously reduced.%针对大功率发动机活塞在周期性爆发压力、活塞销反力、高温及循环热载荷复杂工况下经常出现的蠕变-疲劳故障现象,通过试验和数值模拟方法研究材料、高温等因素对蠕变-疲劳故障的影响规律,提出基于故障物理的机械可靠性设计分析技术,以故障机理为单元,分别建立蠕变、疲劳及其交互作用的损伤模型,利用损伤等效方法建立基于线性损伤累积的活塞蠕变-疲劳可靠性模型,对活塞可靠度、灵敏度和可靠寿命进行了分析计算,并对计算方法进行了对比验证,计算结果与传统蒙特卡洛法计算结果接近,但计算量明显减少.
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