Elucidating ballistic resistance mechanism and pattern of polyurea-coated ceramic/metal composite structures: A numerical and theoretical approach

A critical challenge for polyurea-coated ceramic/metal composite structures, frequently employed in used as military applications, is understanding how the polyurea layer thickness influences ballistic behavior and patterns. This study examined the energy absorption of each constituent material within the composite structure using numerical and theoretical approach, revealing a significant transition in failure mechanisms and damage progression within ceramic blocks as the polyurea layer thickness increased. Utilizing dimensional analysis, a semi-empirical model was established to predict the ballistic limit. The ballistic limit of the composite structure initially increased with increasing of the polyurea thickness but subsequently decreased, corroborating the transition. Additionally, a theoretical model was constructed to determine the ballistic limit velocity in relation to thickness ratios, leading to the proposal of two types of optimization problems based on this model. These results indicated that the thickness of polyurea should be chosen wisely for optimization problem of ballistic performance, even without any mass or volume constraints. This research sheds light on the influence of the polyurea layer on the ballistic performance of composite structures, offering valuable insights for the design of novel composite structures.