Numerical simulation and mechanism analysis of thermal fatigue crack for low-alloy steel brake disc of high-speed train

Abstract

ABSTRACTHigh-speed train brake discs face severe service conditions and subsequently risk of material failure during emergency braking. Thermal fatigue cracking is a major concern leading to catastrophic disc failure and is regarded as a primary service bottleneck in rapid rail transportation. Our proposed work establishes a numerical prediction model to estimate thermal fatigue crack initiation and propagation in low-alloy steel. We used a modified Cockcroft-Latham criterion and material property tests to determine the critical crack initiation value. Through numerical simulations and in-situ experiments, we observed plastic deformation at the median temperature of the thermal fatigue cycle and found that tailored material composition improves brake disc fatigue performance. This research aims to enhance understanding of the cracking mechanism and improve the reliability of brake systems for high-speed trains.KEYWORDS: High-speed trainbrake discnumerical simulationcrack damage modelthermal fatigue crack Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was funded by the National Natural Science Foundation of China (Grant No 51975316), National Natural Science Foundation of China (Grant No. 51975320), the Beijing Natural Science Foundation (No. M22011), and the National Key R&D Program of China (No. 2017YFB1103300).