Fastening clips, though seemingly minor components, are crucial for maintaining the stability and smoothness of railway tracks. However, clip fatigue fractures have been frequently encountered in high-speed railways due to high-frequency excitations. This study develops an efficient predictive model for clip fatigue life assessment using a particle swarm optimization algorithm (PSOA). Firstly, the central axis of an ω-type fastening clip with spatially variable curvature is mathematically described via ten independent parameters. By employing the modal superposition method (MSM) and PSOA, we have derived vibration equations of a prestressed clip. This approach addresses nonlinear contact through simplified constraints, reduces degrees of freedom, and achieves faster numerical convergence than traditional 3D finite element (FE) models, thereby enabling efficient prediction of fatigue life due to vehicle-track dynamic interactions. The model’s reliability has been validated by existing numerical results and experimental studies. Subsequently, high vibration, high stress, and low fatigue life regions, as well as the specific location most prone to fracture, are identified based on the spatial distribution of clip dynamic responses. The potential causes of stress concentration at the critical location are explored by examining the clip’s geometric characteristics, including curvature, torsion, and their derivatives. Finally, control thresholds for the amplitude of short-wavelength irregularities and vertical vibration displacement of clips are proposed to meet the fatigue life requirement. The current work provides guidance for the maintenance and management of high-speed railway fastening clips and inspires the optimization of the clip configuration.

中文翻译：

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基于粒子群优化算法的高速铁路扣件夹高频疲劳寿命高效预测模型

紧固夹虽然看似微不足道，但对于保持铁路轨道的稳定性和光滑度至关重要。然而，由于高频激励，在高速铁路中经常遇到夹子疲劳断裂。本研究使用粒子群优化算法 （PSOA） 开发了一种有效的弹夹疲劳寿命评估预测模型。首先，通过十个独立参数对具有空间可变曲率的 ω 型紧固夹的中心轴进行数学描述。通过采用模态叠加法 （MSM） 和 PSOA，我们推导出了预应力夹的振动方程。与传统的 3D 有限元 （FE） 模型相比，这种方法通过简化的约束来解决非线性接触问题，减小了自由度，并实现了更快的数值收敛，从而能够有效地预测由于车辆与轨道动态相互作用而导致的疲劳寿命。该模型的可靠性已通过现有的数值结果和实验研究得到验证。随后，根据剪辑动力学响应的空间分布确定高振动、高应力和低疲劳寿命区域，以及最容易断裂的特定位置。通过检查线夹的几何特性（包括曲率、扭转及其导数），探讨了应力集中在临界位置的潜在原因。最后，为满足疲劳寿命要求，提出了短波长不规则幅值和夹子垂直振动位移的控制阈值。目前的工作为高速铁路紧固夹的维护和管理提供了指导，并激发了夹子配置的优化。