ABSTRACT

In this paper, modelling methods are developed to achieve dynamics exploration for the vehicle–track system and its substructures. First, a coupled model, with the satisfaction of wheel–rail displacement compatibility and force equilibrium within each time step, is constructed for the characterisation of vehicle–track interaction, where the vehicle is modelled as a multi-rigid-body system, the ballasted tracks are modelled as a combination of elasticity, damping and mass structures by finite-element method, and time-varying wheel–rail contacts in geometry, creep and force are depicted at the three-dimensional space. On the foundation of vehicle–track interactions, a multi-finite-element coupling method originated from the energy variation principle is presented to integrate multiple substructures, such as bridge and soil subgrade, into the vehicle–track coupled system. Due to the variation of dominant frequencies of the vehicle–track system and its substructures, a multi-time-step solution method is proposed to achieve a hybrid solution of fine and coarse time step size for the vehicle–track system and substructure system, respectively. Numerical examples are presented to show the accuracy and practicality of the proposed model and methods.

摘要

在本文中，开发了建模方法来实现车辆-轨道系统及其子结构的动力学探索。首先，构建了满足轮轨位移相容性和每个时间步内力平衡的耦合模型，用于表征车辆-轨道相互作用，其中车辆被建模为多刚体系统，有砟通过有限元方法将轨道建模为弹性、阻尼和质量结构的组合，并在三维空间描绘几何、蠕变和力的时变轮轨接触。在车辆-轨道相互作用的基础上，提出了一种源自能量变化原理的多有限元耦合方法，用于整合桥梁和土路基等多个子结构，进入车辆​​-轨道耦合系统。针对车辆-轨道系统及其子结构主频的变化，提出了一种多时间步求解方法，分别实现车辆-轨道系统和子结构系统的细、粗时间步长的混合求解。 . 数值例子展示了所提出的模型和方法的准确性和实用性。