轮轨滑动磨损对应力和温度影响的研究OA北大核心

Sliding contact between wheel and rail will occur when the train is starting,braking,or passing through curved tracks and long-heavy down grades.In subways,the sliding contact is more frequent.The wear caused by sliding contact has a significant effect on the stress and friction heat of contact region.According to the numerical calculation method and friction heat transfer theory,a wheel-rail contact wear model and a friction heat transfer model are established.The wear-dependent contact stress is introduced,and a moving heat source is employed to simulate the friction heat.The temperature-dependent material parameters are adopted in models.The influences of wear on stress and temperature are studied.The results show that,with the increase of sliding distance,the wheel-rail contact patch becomes larger,the shape of contact patch changes from convex to flat,the maximum contact stress descends gradually,and the distribution of contact stress tends to be uniform.When the wear depth of wheel exceeds 0.2 mm,the node temperature values calculated by the initial contact stress are higher than those calculated by the wear-dependent contact stress.And as the sliding distance increases,the difference in temperatures increases gradually.At the end of sliding contact,the maximum temperatures of wheel and rail calculated by the initial contact stress are 113.9 ℃ and 61.0 ℃ respectively higher than those obtained by the wear-dependent contact stress.The research results indicate that the wear obviously influences the contact stress and friction heat,and these influences should be fully considered when calculating the stress and friction heat.