Kang Guozheng

Fatigue crack growth life prediction of railway hollow axis with flaws under press fitting and measured dynamic stress spectrum

Damage tolerance analysis and residual life of the train hollow axis at the speed of 385 km/h were conducted with measured stress spectrum and press fits of wheel-axle and gear-axle in the framework of linear elastic fracture mechanics by 20-node isoparametric singular element in the close vicinity of crack tip. For this purpose, a postulated semi-elliptical surface crack with an initial depth of 2 mm was inserted into the shaft shoulder, wheel-axle pressing area, wheel-gear transition zone, gear-axle pressing area and axle body, respectively. Numerical simulation shows that the fatigue cracking lives of wheel-gear release groove, shaft shoulder, wheel-axle pressing area, and gear-axle pressing zone are approximately 79, 587, 8239 and 3725 thousand kilometers, respectively. Due to a typical compressive stress near the middle of axis body, it is identified that the crack is arrested. Research results provide important theoretical basis and scientific support for the safety design and reliable service of the hollow axle of next generation China high-speed train.