Dynamic responses of aluminum alloy plates coated with polyurea elastomer subjected to repeated blast loads: Experimental and numerical investigation

As one of the commonly used component units of engineering structures, aluminum alloy plates will likely suffer from multiple blast loads in terrorist bombing attacks and industrial explosion accidents. Given such structures, the research of technical measures to resist extreme blast disasters is an important topic. Polyurea, is a potential excellent strategy for improving the blast resistance of aluminum alloy plates, with a promising application prospect. This study experimentally investigated the dynamic response and damage characteristics of polyurea-coated aluminum alloy plates under repeated blast loads, and the microscopic characteristics of polyurea material and Vickers hardness properties of aluminum material after loading were analyzed. Based on the developed numerical model, the plastic deformation and energy propagation laws of composite plates were analyzed. Finally, a parametric study on the coating position of polyurea, blast scaled distance, and number of blasts was conducted. The damage regularity of the aluminum plate was obtained, and the damage assessment was performed. The results revealed that polyurea coated on the back or double sides of the aluminum plate could exhibit improved blast resistance. Under repeated blasts, compared with that of the Category A plate (uncoated polyurea), the Category B plate (coated with polyurea on the back side) exhibited improvements of 33.9% and 31.3% in the local and overall deformation resistances, respectively. The Category C plate (coated with polyurea on both sides) exhibited improvements of 19.3% and 22.5%, respectively. Polyurea significantly alleviated the damage of the aluminum plates after two explosive loads.