Performance of the polyurea-coated steel tank under air blast load: a numerical study

Steel tanks are used in industries for several purposes, such as the storage of chemicals, water, oil, petroleum products, etc. These steel tanks are frequently exposed to internal explosions due to flammable vapor clouds and external explosives. Generally, two types of blast loads are identified, including surface blast load and air blast load. The air blast load is classified into cylindrical and spherical charges. This study attempted the air blast load mitigation of steel tanks using polyurea coating. A numerical model was developed to evaluate the response of the steel tank under air blast load in terms of internal energy, kinetic energy, strain energy, von-Mises stress, normalized base shear, and side overpressure response. In this regard, two different thicknesses (3.5 and 4.0 mm) of the polyurea coating were used. The model was successfully validated utilizing the previous experimental data. The numerical results indicated that the blast mitigation of steel tanks was effectively enhanced by applying the polyurea coating. In addition, the blast resistance increased with the increase in the thickness of the coating, where a reduction of 70% and 72% in displacements under different air blast loads were observed at the polyurea layer's thicknesses of 3.5 and 4.0 mm, respectively.