Mechanical-Thermal-Electrical Coupling Modeling and Temperature Rise Characteristic of a Parallel Groove Clamp With Improved Representation of Contact Interactions

The electrical contact resistance and thermal contact resistance caused by the actual rough surfaces of parallel groove clamps exist during contact interactions, which affects the heat generation rate and thermal conductivity, and then the accuracy of multifield coupling numerical simulation. Thus, first, a mechanical-thermal-electrical coupling model of the parallel groove clamp is created based on the improved representation of contact interactions. Then, a progressive sequential coupling method is proposed to improve the calculation accuracy and efficiency of the multifield coupling. Meanwhile, the validity of the coupling model is verified by electrical resistance and temperature measurement experiments. Finally, the temperature rise characteristic of the parallel groove clamp is analyzed under normal and large current impact conditions. The results show that the experimental and numerical electrical resistance and temperature show a good agreement. The electrical resistance of parallel groove clamps stabilizes when the preload force is greater than the critical value, 5000 N. The highest temperature of parallel groove clamps is always located at the contact edge between the upper clamp block and branch line, and the influence of current intensity on temperature rise is significant under normal conditions, while the effect of preload force is less. The large current impact mainly affects the transient temperature rise. However, the effect of the large current impact on steady-state temperature is negligible.