Impact damage of steel plate and welding steel plate under multiple Underwater Explosions

In order to study the anti-explosion and anti-shock ability of warship structure under multiple underwater explosion loads, several underwater explosion tests of marine A32 backspace steel plate and welding plate of 5mm and 12 mm were carried out based on the underwater explosion bulging test, the plastic deformation history of steel plate and welding plate was obtained, the deflection and thickness reduction rate of the points along radius in impact area of steel plate and welding plate were measured and calculated. The plastic deformation law of steel plate and welding plate was analyzed. The results show that under the action of multiple underwater explosion loads, the plastic deformation morphology of welding plate and steel plate is in the shape of spherical crown, and their thickness reduction rate decreases at first and then increases from the center position to the boundary. But the deflection of the welding plate is less than that of the steel plate. The deformation mode of A32 steel plate is mainly bending and stretching, and the welding plate is mainly bending. The continuous increase of underwater explosion load leads to the tensile fracture at the center and boundary of the steel plate, while the brittle fracture occurs in the weld and its heat-affected zone of the welding plate. © 2020, Editorial Office of Journal of Vibration and Shock. All right reserved.