A Deterministic Model for Contact Surfaces at Dielectric Interfaces Subjected to an Electrical Field

This paper presents theoretical and experimental studies aiming to explore the effects of the elastic modulus and surface roughness on tangential AC breakdown strength (BDS) of interfaces between polymers. Four different polymers with different elastic moduli were tested. The interfaces were formed between identical specimens and were AC breakdown tested at various contact pressures. In addition, interface surfaces were polished using four different sandpapers of different grit sizes to study the effect of surface roughness. A deterministic model based on the tribology of solid surfaces was proposed to simulate the deformation of the surface asperities in 3D as a function of the contact pressure, surface roughness, elastic modulus, and hardness of an interface. The simulation results were correlated with the results of the AC breakdown experiments, and they elucidated how cavities were linked at solid-solid interfaces and enabled the estimation of the gas pressure inside the cavities under different circumstances (roughness, elasticity, and pressure).