Dynamic response and damage characterization of the clamped plate subjected to underwater explosions with double charges

Understanding the dynamic responses and damage mechanisms of thin-walled metal structures under complex loading conditions is crucial for the safety of marine vessels. Previous research has predominantly focused on the dynamic response behavior of thin-walled structures under sequentially repeated loads, without considering the damage effects induced by the simultaneous application of multiple loads. This study employs a combination of experimental and numerical approaches to systematically investigate the dynamic responses and damage characteristics of thin-walled steel plates subjected to simultaneous double-charge underwater explosions. The experimental and simulation results reveal that the sustained propagation of transmitted waves in a water-backed environment influences the bubble expansion behavior, resulting in the deformation rebound of the plates. Furthermore, the concave deformations in the plate are aligned along the symmetry plane of the two charges, resulting in the development of a trace line during the deformation process. In addition, the influence of the pre-pierced holes on the plate deflection within the plastic range is negligible. An optimal spacing range for double-charges at a given standoff distance is identified, which results in the maximum plate deflection. These findings provide valuable insights into the damage to thin-walled structures under simultaneous multi-load conditions and offer new perspectives for enhancing protective design in ship engineering.