Residual life prediction of a deep-rolled axle with flaws based on the extended finite element method

Abstract

<p indent="0mm">Railway axles are subjected to many load cycles during an operation period, and the axle integrity may be destroyed, so railway axles risk fatigue failure. To prevent axle fatigue failure, the residual life of an axle with defects must be evaluated. The residual stress field of axle depth direction was reconstructed using SIGINI and the quadratic iteration method to study the fatigue crack propagation behavior of an EA4T alloy steel axle after deep rolling treatment. Simultaneously, the axle press-fitting process and the actual load spectrum of an axle in service were considered comprehensively, and the extended finite element method was adopted to calculate the stress intensity factor of an EA4T axle with an initial crack. The residual life of a full-size EA4T axle was predicted using the fracture mechanics evaluation method. The results show that the crack will not propagate when the crack depth direction is within the range of the residual stress layer. When the crack is located in the middle of the axle body, the critical failure sizes of the power axle and nonpower axle are 7 and <sc>9 mm,</sc> respectively, and the corresponding residual lives are 471300 and <sc>1013500 km,</sc> respectively. When the crack is located at the inner arc transition of the wheel, the critical failure sizes of the power and nonpower axles are 4.5 and <sc>5 mm,</sc> respectively. The results of this study can provide a reference for optimizing the maintenance interval of an EA4T axle after deep rolling treatment.