Analytical study of local damage on concrete slab subjected to a contact explosion

Local damage on concrete slab subjected to a contact explosion includes explosive cratering on the front face and spalling or perforating on the back face. It is a subject that has been studied by many investigators for many years for many purposes. However, computational methods on explosive spallation or perforation are rare while they are significant for the design of warhead, the protective structure and engineering blasting. In this paper, the dynamic behavior of material was described by rigid-plastic model, and the material resistance of concrete slab subjected to contact explosions was derived by utilizing limit equilibrium theory. Combined with the initial and boundary conditions, the formulae of the threshold thickness have been derived, which can predict the categories of local damage on concrete slab under contact explosion loads. Besides, a non-dimensional impact factor was derived, which reflects the integrated nature of explosive sources and material resistance. Finally, analysis study of the results of numerical simulation and the derived equations proved the rationality of the proposed calculation methods