Numerical study of the effect of polyurea on the performance of steel plates under blast loads

•Polyurea-steel bilayer plates are modeled under simulated blast loading.•The effects of thickness and location of polyurea on blast mitigation are studied.•The distinction between direct pressure vs. wave loading is analyzed.

We present the results of our numerical simulation of the dynamic response and deformation of 1 m diameter circular DH-36 steel plates and DH-36 steel-polyurea bilayers, subjected to blast-like loads. Different thicknesses of the polyurea are considered and the effect of polyurea thickness on the performance of steel plates under blast loads is investigated. For each polyurea thickness, we have simulated three cases: (1) polyurea cast on the front face (loading face); (2) polyurea (of the same thickness) cast on the back face; and (3) steel plate of a suitable thickness such that the areal density remains the same in all three cases. Two types of loading are applied to the polyurea-steel system: (1) direct application of pressure on the bilayer system, (2) application of pressure through a separate medium (soft polyurethane or water). The resulting differences are demonstrated and discussed throughout the paper. For the constitutive properties, we have used physics-based and experimentally-supported temperature- and rate-sensitive models for DH-36 steel and polyurea, including, in the latter case, the pressure effects.Results from the simulations reveal that, when the polyurea layer with enough thickness is cast on the back face of the plate, the bilayer demonstrates superior performance relative to the other two cases. The differences become more pronounced as the polyurea thickness (maintaining the same areal density in the three cases) becomes greater.