Predict the rupture of transformer tanks with static FEM analysis

Electrical errors inside the transformer may lead to an arc discharge with high energy peaks. These causes pressure shock waves which break the tank open and lead to oil leakage. In order to withstand this overpressure the stresses in the tank wall, especially in welds, must be lower than the tensile strength of steel. To reduce the complexity of dynamic behavior the standard SN 14.1h defines a corresponding static pressure which can be used in a FEM calculation to predict the stresses in the tank. In this paper we compare simulations of a transformer tank under static overpressure with different material models to find a fast solution for validate a design with respect to withstanding the overpressure caused by an arc discharge.