Abstract
The aim of the presented work was to study the method reducing the stress level in epoxy-based products, by application of stress-relief holes. The optimal geometry of relief holes, as well as their locations were found by numerical simulations. Two design variants (with drilled– and cast holes) were considered in numerical analysis, and selected geometrical configurations were also tested by experimental tests. The obtained results allowed formulate the number of practical recommendations for production of medium voltage devices. It was shown that proper application of relief holes in case of brittle material can bring positive effects and reduce the probability of material failure.