This article focuses on the time-variant reliability assessment of riveted lap joint structure subjected to fatigue. A physics-based fatigue crack growth model that can take the crack closure into account is derived to calculate the crack length at different time under arbitrary loading. In addition, several uncertainties are quantified, including the material, initial crack size, and loading condition. The stationary random loading is a common service environment in practice, in which the stress range and stress ratio vary with constant statistical characteristics (the mean and standard deviation). The time-variant fatigue reliability of riveted lap joint under stationary random loading is assessed by introducing the outcrossing concept. The experimental data of 2024-T3 aluminum alloy riveted lap joint under constant amplitude loading are used to validate the physics-based fatigue crack growth model. It is verified that this proposed model can predict the fatigue life probability distribution with a reasonable accuracy. In addition, the simulation of riveted lap joint under stationary random loading is performed. The time-variant fatigue reliability is evaluated. The results with or without considering crack closures are also compared. It is noted that the results from the time-variant fatigue reliability assessment considering crack closure has higher reliability level.

本文重点研究铆接搭接接头结构疲劳时变的可靠性评估。推导了可以考虑裂纹闭合的基于物理的疲劳裂纹扩展模型，以计算任意载荷下不同时间的裂纹长度。此外，还量化了一些不确定性，包括材料，初始裂纹尺寸和加载条件。静态随机载荷是实践中的常见服务环境，其中应力范围和应力比以恒定的统计特征（均值和标准差）变化。通过引入交叉概念来评估固定随机载荷下铆接搭接接头的时变疲劳可靠性。以2024-T3铝合金铆接搭接接头在恒定振幅载荷下的实验数据验证了基于物理的疲劳裂纹扩展模型。验证了该模型可以合理地预测疲劳寿命概率分布。此外，还进行了静态随机载荷作用下铆接搭接接头的仿真。评估随时间变化的疲劳可靠性。还比较了考虑或不考虑裂纹闭合的结果。注意，考虑到裂纹闭合的时变疲劳可靠性评估的结果具有较高的可靠性水平。进行了静态随机载荷作用下铆接搭接接头的仿真。评估随时间变化的疲劳可靠性。还比较了考虑或不考虑裂纹闭合的结果。注意，考虑到裂纹闭合的时变疲劳可靠性评估的结果具有较高的可靠性水平。进行了静态随机载荷作用下铆接搭接接头的仿真。评估随时间变化的疲劳可靠性。还比较了考虑或不考虑裂纹闭合的结果。注意，考虑到裂纹闭合的时变疲劳可靠性评估的结果具有较高的可靠性水平。