Study on the mechanism of near-field underwater explosion on supported thin plates with prefabricated holes

In this study, underwater explosion tests with 2.5 g trinitrotoluene explosive under different fixed plates with prefabricated holes were conducted. The experimental results showed that the air inflow from the prefabricated hole caused the bubble to collapse earlier with an increase in the hole diameter. In addition, the deformation mode of the thin plate transitioned from “convex” to “concave” (up to down). Next, the coupled Eulerian-Lagrangian method was used to perform the corresponding numerical simulation. The accuracy of the numerical simulation method was verified through a comparison with the experimental data. In addition, a series of numerical simulations were conducted with different prefabricated-hole diameters, blast distances, and prefabricated-hole shapes. The results showed that the bubble-pulsating water jet substantially influenced the deformation of the thin plate when the diameter of the prefabricated hole was within the theoretical maximum bubble radius. When the blast distance was within the theoretical maximum bubble radius, the thin plate was subjected to only a single bubble pulsation owing to the air inflow from the prefabricated hole.