考虑尖轨变截面廓形的轮轨接触与磨耗分析

为研究尖轨变截面对曲尖轨轮轨接触行为和磨耗分布的影响，提出了一种适用于道岔区的三维非对称接触几何算法，该算法可计算车轮与曲尖轨间的真实法向间隙. 使用SIMPACK建立车辆-道岔多体动力学模型，获得仿真结果；利用考虑变截面的接触模型与英国谢菲尔大学提出的USFD磨耗模型计算曲尖轨磨耗. 研究结果表明:1） 以S1002CN车轮与12号道岔曲尖轨为例，轮对摇头角与尖轨变截面均会引起轮轨法向间隙沿接触斑纵向非对称分布，从而导致接触斑形状与应力沿接触斑纵向非对称分布；当摇头角为10 mrad，横移量为7.5 mm时，本文算法得到的接触斑面积比未考虑尖轨变截面和摇头角的简化算法所得结果大9.2%. 2） 以CRH3型车与12号曲尖轨道岔为研究对象，简化算法得到的最大磨耗深度为本文算法所得结果的0.75倍. 

Analysis of Wheel-Rail Contact and Wear Considering Variable Cross-Sections of Switch Rail

To investigate the influence of variable switch rail cross-sections on wheel-rail contact behaviors and the wear distribution of the curved switch rail, a three dimensional (3D) asymmetric contact geometry method for the turnout area was proposed, which could calculate the real normal gap between the wheel and curved switch rail. The vehicle-turnout multi-body dynamics model was initially built by SIMPACK to obtain simulated results. And then the wear depth of the curved switch rail was calculated by the contact model considering variable cross-sections and the USFD wear model proposed by University of Sheffield. The results show that: 1) Taking the S1002CN wheel profile and No. 12 curved switch rail for examples, both the wheel-set yaw angle and variable cross-sections result in the asymmetric distribution of wheel-rail normal gap along the longitudinal direction within the contact patch. Therefore, the normal gap causes the contact patch shape and stress distribution asymmetric along the longitudinal direction within the contact patch. When the wheel-set yaw angle is 10 mrad and the lateral displacement is 7.5 mm, the area of contact patch obtained by the proposed method is 9.2% larger than that solved by the simplified method without considering the variable cross-sections and yaw angle. 2) Taking the CRH3 vehicle and No.12 curved switch blades as the research objects, the maximum wear depth calculated by the simplified method is 0.75 times as large as that according to the proposed method.