The computer simulation of the structural material is required to study the stress-strain state of the structural material of the high-pressure hull (in particular, the heat accumulator body). Laboratory experiment requires significant financial expenses, which is a significant drawback of this type of study. Therefore, the authors considered finite element modeling of structural material by adapting modern software systems for calculating the considered models. A modern design solution for high-pressure hulls of heat accumulators made of non-prestressed reinforced concrete involves the usage of heavy reinforcement cement as a structural material. The proposed method allows gaining rather certain calculations avoiding time-consuming laboratory research.