A DYNAMIC ELECTRO-THERMO-MECHANICAL MODEL OF DIELECTRIC BREAKDOWN IN SOLIDS USING PERIDYNAMICS

摘要

The electro-thermo-mechanical breakdown of dielectric solids is modeled using peridynamics to describe the brittle fracture of a material under high electric fields. A coupled electrostatic, elastodynamic, thermodynamic model is used wherein electrostatic forces are computed and applied to the mechanical model and temperature effects are included. Fracture is simulated using peridynamics, a reformulation of elasticity that incorporates material failure. Coupling occurs between the electrostatic and mechanical forces and also the electrical material properties: specifically, the Lorentz and Kelvin forces are used to couple the electrostatic fields to the stress fields, conductivity is treated as nonlinear and a function of temperature, and mechanical damage is used to alter the permittivity. Results demonstrate that the method is capable of reproducing branching breakdown patterns seen in experiments using a deterministic method.