Over the past few years, a number of implicit/explicit finite element models have been introduced for the purpose of tackling the problems of wheel–rail interaction. Yet, most of those finite element models encounter common numerical difficulties. For instance, initial gaps/penetrations between two contact bodies, which easily occur when realistic wheel–rail profiles are accounted for, would trigger the problems of divergence in implicit finite element simulations. Also, redundant, insufficient or mismatched mesh refinements in the vicinity of areas in contact can lead to either prohibitive calculation expenses or inaccurate implicit/explicit finite element solutions. To address the abovementioned problems and to improve the performance of finite element simulations, a novel modelling strategy has been proposed. In this strategy, the three-dimensional explicit finite element analysis is seamlessly coupled with the two-dimensional geometrical contact analysis. The contact properties in the three-dimensional finite element analyses, such as the initial “Just-in-contact” point, the exact wheel local rolling radius, etc., which are usually a priori unknown, are determined using the two-dimensional geometrical contact model. As part of the coupling strategy, a technique has been developed for adaptive mesh refinement. The mesh and mesh density of wheel–rail finite element models change adaptively depending on the exact location of the contact areas and the local geometry of contact bodies. By this means, a good balance between the calculation efficiency and accuracy can be achieved. Last, but not least, the advantage of the coupling strategy has been demonstrated in studies on the relationship between the initial slips and the steady frictional rolling state. Finally, the results of the simulations are presented and discussed.

中文翻译：

---

使用耦合策略提高轮轨相互作用的有限元模拟性能

在过去的几年中，为了解决轮轨相互作用问题，引入了许多隐式/显式有限元模型。然而，大多数有限元模型都会遇到常见的数值困难。例如，两个接触体之间的初始间隙/穿透（在考虑实际轮轨轮廓时很容易出现）会引发隐式有限元模拟中的发散问题。此外，接触区域附近的冗余、不足或不匹配的网格细化可能导致计算费用过高或隐式/显式有限元解不准确。为了解决上述问题并提高有限元模拟的性能，提出了一种新的建模策略。在该策略中，三维显式有限元分析与二维几何接触分析无缝耦合。三维有限元分析中的接触特性，例如初始“刚刚接触”点、精确的车轮局部滚动半径等，通常是先验未知的，可以使用二维几何模型来确定。接触模型。作为耦合策略的一部分，已经开发了一种用于自适应网格细化的技术。轮轨有限元模型的网格和网格密度根据接触区域的确切位置和接触体的局部几何形状自适应变化。通过这种方式，可以实现计算效率和精度之间的良好平衡。最后但并非最不重要的一点是，耦合策略的优势已在初始滑移与稳定摩擦滚动状态之间关系的研究中得到证明。最后，提出并讨论了模拟结果。