Effect of Tread Scratch on Fatigue Life of Wheels in High -speed EMU under Low Temperature Servicing Condition

摘要

In order to study the influence of scratches on the fatigue life of CRH5 EMU wheels under -40°C servicing condition, a dynamic model of the vehicle-rail system is established along with the contact model of the scratched wheels. Considering the irregular and typical working condition of the railway line, a random load spectrum and a cyclical wheel-rail impact load spectrum are obtained. The S-N character of the wheel material is obtained according to a series of fatigue test in serving environment -40°C. Using the finite element quasi-static superposition method, the fatigue life of the wheels with and without scratch are compared, and then the fatigue life of the scratched wheel is evaluated. The results show when the scratch length L_R≤ 20 mm, the fatigue life of the scratched wheel is less affected by the wheel-rail impact caused by scratch; when the scratch length L_R>20 mm, the fatigue life decrease quickly, less than 1e6km, affecting the safety of the EMU.