Voltage Breakdown in Random Composites

Voltage breakdown is a strongly localized phenomenon in random‐microstructure composites because the different dielectric constants of metal and polymer matrix turn a uniform external field across the structure into spatially non‐uniform local fields. The authors show that rather small computer models are sufficient to extract reliable estimates for the breakdown fields in lab‐scale samples. The Figure shows a cut through a periodic unstructured mesh of a Monte Carlo model with 27 spheres.