Mazilu Traian, Dumitriu Mădălina, Răcănel Ionuț-Radu
Department of Railway Vehicles, University Politehnica of Bucharest, 060042 Bucharest, Romania.
Department of Strength of Materials, Bridges and Tunnels, Technical University of Civil Engineering Bucharest, 020396 Bucharest, Romania.
Materials (Basel). 2023 Feb 12;16(4):1531. doi: 10.3390/ma16041531.
The rail pad is the elastic element between the rail and the sleeper that has the role of absorbing the mechanical stresses from the rail and reducing the vibrations and shocks generated by wheel-rail interactions. In this paper, the problem of the influence of the variability of the nonlinear load-deformation characteristic of rail pads (resulting from the manufacturing process) on wheel-rail vibrations is investigated. The limit load-deformation characteristics of a manufactured rail pad and the medium load-deformation characteristic resulting as the arithmetic mean of the two are considered. The nonlinear load-deformation characteristic of the ballast is also considered. All these characteristics are approximated with the help of the bilinear function and are implemented in a track model consisting of an infinite Euler-Bernoulli beam placed on a two-elastic layer continuous foundation with inertial insertion, resulting in a model with an inhomogeneous foundation. The parameters of the inhomogeneous foundation are established from the equilibrium condition under a static load. Wheel-rail vibrations are studied in terms of the contact force and the acceleration of the rail and wheel. The influence of the variability of the elastic characteristics of the rail pad manifests itself in the field of medium frequencies, which amplify or attenuate the vibration levels in certain bands of one-third of an octave.
轨枕垫是轨道与轨枕之间的弹性元件，其作用是吸收来自轨道的机械应力，并减少轮轨相互作用产生的振动和冲击。本文研究了轨枕垫非线性载荷-变形特性（由制造工艺导致）的变异性对轮轨振动的影响问题。考虑了一个制造出轨枕垫的极限载荷-变形特性以及作为两者算术平均值的中等载荷-变形特性。还考虑了道砟的非线性载荷-变形特性。所有这些特性都借助双线性函数进行近似，并应用于一个轨道模型中，该模型由置于具有惯性插入的双弹性层连续基础上的无限长欧拉-伯努利梁组成，从而得到一个非均匀基础模型。非均匀基础的参数根据静载作用下的平衡条件确定。从接触力以及轨道和车轮的加速度方面研究轮轨振动。轨枕垫弹性特性的变异性影响在中频范围内表现出来，在某些倍频程三分之一频段内会放大或衰减振动水平。
