STUDY ON RESPONSE BEHAVIOR OF ICED CONTACT WIRES UNDER MOVING IMPACT LOADS

The phenomenon of catenary icing poses a severe and persistent threat to the current collection quality and the overall operational safety of electrified railway systems. Currently, mechanical de-icing represents the most extensively applied technique in engineering practice. During the actual operation process, the de-icing device moves continuously along the contact line trajectory while simultaneously applying intermittent impacts. However, the majority of existing research studies are limited to the fixed-point impact mode, which makes it difficult to accurately explain the complex de-icing mechanism. This paper proposes a comprehensive modeling and response analysis method for the mechanical de-icing of iced contact lines subjected to moving impact loads. By establishing a refined finite element model of the iced contact line, the erosion failure of the ice material is defined specifically based on the tensile failure criterion. The simulation of the de-icing process under impact loads is realized by adopting LSDYNA nonlinear finite element explicit dynamic analysis. This study focuses on investigating the wave propagation laws during the de-icing process and exploring the correlation between the stress wave superposition effect and the failure modes of the ice layer. In the numerical examples section, the de-icing rate of the iced contact line and the contact line dynamic response patterns under different moving loading times and loading modes are discussed. The study provides structural displacement and stress response contours that are capable of characterizing the relationships among wave propagation, reflection, superposition, and the de-icing rate. The results indicate that, compared with the fixed-point loading mode, the moving loading mode not only significantly enhances the de-icing rate through the dispersed propagation and superposition of stress waves but also effectively controls the severity of the vertical dynamic displacement of the contact line. The relevant methods and conclusions presented in this paper can provide a valuable theoretical reference for the optimization and design of mechanical de-icing devices.