Damage features of RC slabs subjected to air and underwater contact explosions

Reinforced concrete (RC) slabs are the major components for building structures and underwater engineering plants. However, blast loading, especially from contact explosion, can cause significant damage to the target structures both in air and water. The objective of this paper is to compare the damage characteristics of RC slabs subjected to air and underwater contact explosions. Three methods, i.e. fully coupled Eulerian-Lagrangian (CEL) method, smoothed particle hydrodynamics (SPH) method, and coupled finite element method and smoothed particle hydrodynamics method (FEM-SPH), are first employed to simulate the damage features of an RC slab to air contact explosion. Damage profiles of the RC slab to air contact explosion using the three methods are compared with the experiment results in the literature, and the applicability and suitability of these methods are discussed. Subsequently, the most effective method (i.e., FEM-SPH) is used to describe the dynamic response of the RC slab subjected to underwater contact explosion. Shock wave propagation characteristics from air and underwater contact explosions are discussed. Damage features of the RC slab to air and underwater contact explosions are compared. Damage characteristics and plastic deformation of reinforcement steel bars are also investigated.