Impact of polyurea-coated metallic targets: computational framework

Polyurea elastomer is known to exhibit advantageous impact-mitigation characteristics and thus can improve the dynamic performance of various components and structures. This study identifies the mechanisms of dynamic response of thin metallic plates, covered by a frontal polyurea layer, using a physically verified, custom material model for two-part polyurea implemented within a finite-element-method framework. A linear increase in the ballistic performance of a target with polymer coating is consistent with experimental work captured for the first time in a numerical study. A reported ballistic-limit improvement of 7.4 m s^–1 per millimetre increase of polyurea thickness for frontal-layer thicknesses higher than 4 mm on the thin monolithic plate was established. In contrast, the application of polyurea coating thinner than 4 mm resulted in a diminished ballistic performance of the target. These outcomes are attributed to significant alterations in the energy-absorbing capacity of thin plates with the introduction of the polyurea layer that strongly depend on the impact velocity, polymer thickness, and interfacial interactions.