Railroad vehicles require the use of disc brakes for safety purposes, however, the brakes are susceptible to thermal stress, which ultimately shortens their lifespan. Hence, to accurately predict the life of railway disc brakes in thermal load simulations, the availability of a model that considers spatial and temporal variations of temperature and thermal stress is essential. A non-axisymmetric moving heat source model was successfully developed to address spatial temperature variations (Deressa and Ambie in Urban Rail Transit 8(3–4):198–216, 2022. 10.1007/s40864-022-00176-9), and this study aims to extend this model to predict thermal stress and fatigue life, and assess its effectiveness. The analysis includes braking time thermal analysis, cooling time thermal analysis, and structural analysis. Spatially varying temperature is incorporated into the structural analysis to calculate thermal stress and strain. A fracture mechanics-based fatigue life estimation method is applied to critical areas of the friction surface. The model is implemented on two braking conditions (service and emergency) and two disc geometries (actual and modified). The model successfully resolves spatial heat considerations by estimating maximum stress variations of up to 46 MPa along the disc circumference. Stress differences of 3 MPa and 6 MPa are observed between the leading and trailing edges of the pad trace during late and mid-braking times, respectively. Fatigue life results identify critical positions and directions for fatigue life initiation. Additionally, these results are in accord with previous observations available in the literature. The proposed model can be easily implemented in various sliding friction applications such as drum brakes, engine pistons/cylinders, and camshafts.

出于安全目的，铁路车辆需要使用盘式制动器，但制动器容易受到热应力的影响，最终缩短其使用寿命。因此，为了在热负荷模拟中准确预测铁路盘式制动器的寿命，考虑温度和热应力的空间和时间变化的模型至关重要。成功开发了非轴对称移动热源模型来解决空间温度变化（Deressa 和 Ambie in Urban Rail Transit 8(3–4):198–216, 2022. 10.1007/s40864-022-00176-9），并且该模型研究旨在扩展该模型以预测热应力和疲劳寿命，并评估其有效性。分析包括制动时间热分析、冷却时间热分析和结构分析。将空间变化的温度纳入结构分析中以计算热应力和应变。基于断裂力学的疲劳寿命估计方法应用于摩擦表面的关键区域。该模型在两种制动条件（常用和紧急）和两种制动盘几何形状（实际和修改）上实施。该模型通过估计沿盘圆周高达 46 MPa 的最大应力变化，成功解决了空间热量问题。在制动后期和中期，制动块迹线的前缘和后缘之间分别观察到 3 MPa 和 6 MPa 的应力差。疲劳寿命结果确定了疲劳寿命起始的关键位置和方向。此外，这些结果与文献中先前的观察结果一致。所提出的模型可以轻松地在各种滑动摩擦应用中实现，例如鼓式制动器、发动机活塞/气缸和凸轮轴。