Study On Stress Distribution And Change Between Layers Of Vehicle Semi-rigid Cable Terminal In A Temperature Changing Environment

Ensuring the normal operation of the cable terminal is a necessary condition for the safe and stable operation of the EMU.With the continuous increase of domestic high-speed railway lines,more and more EMUs need to adapt to work in high-altitude and low-temperature environments.As the number of EMU vehicles and cable terminals continues to increase,some cable terminals have exploded during the EMU outbound process.This problem affects the stable operation of the EMU and threatens the power supply system of the EMU.Based on the above problems,relevant studies on the multi-physics characteristics of vehicle cable terminals under complex conditions are carried out.The multi-physics field distribution of the cable terminal in the ideal environment,the sudden change temperature and the heat transfer of the fluid,and the factors of its material properties.This study provides a theoretical basis for the degradation mechanism of the insulation performance of cable terminals,and provides a theoretical guidance in the operation and material selection.In this paper,based on the simulation and experiment,the related research work is carried out.Firstly,thermodynamics and hydromechanics,the cable core is considered as heat source,heat conduction,sudden change of environment temperature and fluid heat transfer are considered,and the interaction of prestress,gravity,thermal expansion and thermal stress are considered.The transient and steady state models of electric thermal force coupling for cable terminals are established.The distribution of temperature,stress and deformation of cable terminal at room temperature and sudden change of ambient temperature is studied.The influence of flow field on the distribution of temperature,stress and deformation of cable terminal is studied.The influence of environmental temperature gradient and rate on multiple physical fields of stress control tube is analyzed.The influence factors of velocity and current carrying capacity on the stress and deformation are also analyzed.In addition,the cold and hot aging test platform and partial discharge test platform are built to verify the conclusion the stress control tube is the weak link.Finally,the orthogonal experiment is designed for the stress control tube.The physical parameters that affect the stress and deformation of the stress control tube are analyzed,and the contribution of each parameter to the stress and shape of the stress control tube is verified.This paper provides a theoretical basis for the study of the causes of insulation aging of cable terminals under rapid temperature change,and provides a theoretical guidance in the use process and manufacturing process to reduce accidents.