Damage characteristics of pre-cracked steel plates subjected to underwater shock wave using FEM-SPH adaptive method

During their operational lifespan, ships and ocean structures are subjected to complex loading conditions, which often lead to crack defects as a common form of damage. To investigate the damage characteristics of cracked steel plates under underwater explosion loads, an experimental study was conducted. In view of the advantages and limitations of FEM and SPH methods in structural damage calculation, an adaptive numerical damage model of pre-cracked structures based on FEM-SPH is constructed. Numerical simulations of underwater contact explosion on pre-cracked steel plates of varying lengths and geometries were performed, enabling a detailed examination of the dynamic response and crack propagation patterns in plates featuring cracks shaped like "−", "T", and "+". The study further explored the influence of crack length and geometry on the resultant damage characteristics. Specifically, variation curves depicting the relationships among crack length, maximum vertical displacement, rupture area, and rupture morphology for "−" shaped cracked steel plates were presented.