Dynamic response and damage characteristics of special blast-resistant door structure subjected to underwater explosion

Abstract

The blast resistance and protection of underwater special blast-resistant door structures were essential research elements for the safety of underwater facilities. This paper aimed to research the dynamic response and damage mode of the plate blast-resistant door structure under the impact load of an underwater explosion. First, a three-dimensional free-field shock wave numerical model was established through LS-DYNA based on the arbitrary lagrangian–eulerian (ALE) algorithm, and the obtained shock wave loads were compared with empirical values to verify the validity and accuracy of the finite element model. Then, to further explore the damage characteristics of the underwater explosion on the plate blast-resistant door structure, a three-dimensional numerical model of the plate blast-resistant door structure under an underwater explosion load was established. The dynamic response and damage of the blast-resistant door structure under different explosive equivalents, propagation medium, explosion distance, hydrostatic pressure and geometric dimensions of structural elements were also analyzed. The results revealed that the damage mode of the blast-resistant door structure was related to its dynamic characteristics and depended on the explosive equivalents, propagation medium, explosive distance, hydrostatic pressure and member size. As the frame beams on both sides were the weak part of the blast resistance, the blast-resistant door structure might cause bending deformation and warpage on both sides of the frame beam and overall structure bending. The research results can provide the characteristics of the underwater explosion load and the mechanism and law of fluid–solid coupling damage of the load on the special blast-resistant door structure, providing a reference for the damage power assessment and blast-resistant door structure design.