Shakedown analysis is an attractive method for determining the capacity of geostructures to sustain repeated loads involving a large number of cycles, e.g. rolling and sliding train wheel loads. Its main advantage is that it comes at a significantly reduced computational cost, compared to standard time-domain analyses. An essential component of shakedown analysis is the derivation of closed-form solutions to compute stresses due to the external repeated loads, a task that is not always feasible for complex problems as the ballasted rail track discussed herein. To tackle this, we present in this paper the use of finite element tools to obtain a quasi-lower-bound shakedown load numerically. The proposed method is based on the computation of the three-dimensional elastic stress field numerically, and the estimation of the shakedown load iteratively via an optimisation subroutine implemented in ABAQUS. Following a short presentation of this concept, we compare the elastic stress fields from models featuring varying degree of complexity, with the aim of identifying an optimal discretisation of the problem. This approach can be used for optimising the design of ballasted track structure, and this concept is briefly presented via a parametric study.

中文翻译：

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基于三维有限元技术的压载轨道结构减震分析

减振分析是一种很有吸引力的方法，可用于确定地质结构承受包括大量循环在内的重复载荷（例如，滚动和滑动火车车轮载荷）的能力。与标准时域分析相比，它的主要优点是显着降低了计算成本。减振分析的重要组成部分是推导闭合形式的解决方案，以计算由于外部重复载荷而产生的应力，这对于本文所述的道rail轨道而言，对于复杂问题并不总是可行的。为了解决这个问题，我们在本文中介绍了使用有限元工具以数值方式获得准较低边界的减振载荷。所提出的方法是基于三维弹性应力场数值计算的，并通过ABAQUS中实现的优化子例程来迭代估算减振负荷。在简短介绍此概念之后，我们比较了具有不同复杂程度的模型的弹性应力场，目的是确定问题的最佳离散化。此方法可用于优化道track轨道结构的设计，并且通过参数研究简要介绍了此概念。