Pressure-Impulse diagrams for assessment of structural response due to a fully confined explosion

Pressure-Impulse (P-I) diagrams provide a quick preliminary tool to assess the dynamic structural resistance to blast loads. In fully confined explosion events, the impulse of the load is infinite, and thus, traditional P-I diagrams cannot represent the structural resistance. In the current study, P-I diagrams are developed for fully confined explosions. A new suggested formulation and definition of the impulse are introduced, such that the P-I diagram includes two pressure asymptotes, contrary to traditional approaches. Dimensional analysis is performed for linear-elastic, elas-tic-plastic and elastic-plastic with hardening structures. Based on the results, the study suggests a semi-empirical model that quickly evaluates the P-I diagrams for the cases presented in this study with high accuracy, without performing additional structural analyses that may be expensive in terms of computational costs. The suggested method has been verified with a direct approach for constructing the P-I diagram through a case study.