Optimal Design of Curved Rail Profile for Wear and Stress

In order to alleviate the phenomenas of the severe wear and large contact stress of the heavy-haul curve rails, the method is established about the asymmetric optimization design of curve rail profiles, which analyzes the influences of the different optimized strategies on the wheel-rail wear and contact stress. Based on the vehicle-track dynamics theory, wheel-rail wear theory, Hertz contact theory, genetic algorithm, and analytic hierarchy process, the method set the coordinates of discrete points of the rail profile as optimization variables, set vehicle dynamics performance indicators and rail geometric characteristics as constraints. With wear and stress as the optimization targets, a symmetrical optimization design method of curved rail profiles is obtained. The above method to study three optimization design strategies which only consider wear, stress only and wear-stress at the same time are studied in the optimization iteration. The results show that, compared with the actual measured rail profile on site, the strategy, only considered wear, causes the stress to rise by 24%, and the comprehensive evaluation index rises by 8%. The method, only considered stress, causes the wear to rises by 149%, and the comprehensive evaluation index rises by 258%. The method of optimizing the wear and stress in the same time makes the wear drop by 32%, makes the stress decrease by 22%, and the comprehensive evaluation index drops by 17%. The optimal rail profile curve passing performance and vehicle running adaptability perform well. The optimal rail profile does not aggravate the wheel flange wear while providing a larger wheelset lateral displacement, which is more conducive to curve passing. With the increase of speed and load, the wear index and contact stress and derailment coefficient are smaller than those of the measured profile. © 2022 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.