轮轨三维非线性静态接触应力及其影响因素分析*

摘要

Wheel-rail contact is the key issue in safe operation of the high-speed train.Researching on three- dimensional nonlinear static wheel-rail contact stress and its influential factors is the key to solving these problems.By using finite element analysis software-ANSYS,a three-dimensional finite element model of wheel-rail and face to face contact element between the wheel-rails are set up.TB tapered tread and CHN60 steel rail are calculated according to static contact,and the effect of wheel weight and material model on the contact patch shape and area is analyzed.At the same time,the solutions are compared with Hertz theoreti-cal solutions,then the effect of the average contact stress and wheel-rail Mises stress is analyzed.Further-more,the elastic foundation is simulated by using a spring element with consideration of the influence of foundation stiffness on the static normal contact stress of wheel-rail.The results show that the contact patch area and shape of wheel-rail are the main influencing factors to contact stress of wheel-rail;the con-tact patch shape of wheel-rail is different from the elliptical contact patch in Hertz theory,and with the in-crease of wheel load,the gap in the contact patch area becomes greater gradually,resulting in a difference in the average contact stress of wheel-rail;the contact area of elastic material is smaller than that of elastic- plastic material;the part between wheel contact inevitably appears plastic deformation;the normal contact stress decreases with the decrease of foundation stiffness,but excessively small foundation stiffness will in-crease ground deformation,which is harmful to long-term operation of the train.%轮轨接触是高速列车运营安全中的关键问题，研究轮轨三维非线性静态接触应力及其影响因素是解决这些问题的关键。利用有限元分析软件 ANSYS，建立三维轮轨有限元模型，轮轨之间建立面面接触单元，对 TB锥形踏面和CHN60钢轨静态接触进行计算，分析轮重和材料模型因素对接触斑形状和面积的影响，并与 Hertz理论解进行对比，进而分析平均接触应力、轮轨 Mises应力的影响，再利用弹簧单元模拟弹性地基，考虑地基刚度因素对轮轨静态法向接触应力的影响。结果表明：轮轨接触斑面积和形状是轮轨接触应力的主要影响因素；轮轨接触斑形状与 Hertz理论的椭圆接触斑存在差异，随着轮重增加，接触斑面积的差距逐渐越大，导致轮轨平均接触应力不同；弹性材料的接触斑面积小于弹塑性材料接触斑面积；轮轨接触不可避免的出现塑性变形；法向接触应力随着地基刚度减小而减小，但过小的地基刚度会增加地基变形，对列车长期运行不利。