Modeling of the Minehunters Hull Strenght

Abstract

The paper presents problems of modeling the ship’s hull subjected to the load of shock wave associated with non-contact underwater explosion. The article presents equations for describing the parameters of shock wave subjected to an impulse load. The paper presents a proposal of identification of a degree of hazard the ship’s hull forced from underwater explosion. A theoretical analysis was made of influence of changes of hull structure in vicinity of hull. Modeled signals and hull structure were recognized within sensitive symptoms of three sub models: model of hull structure, model of impact and model of propulsion system. All sub models allow testing forces and their responses in vibration spectrum using SIMULINK software and FEM models. The results of testing allowed performing simulations of a similar nature to the actual loads of underwater explosions. Virtual model of the hull of the ship responds in a similar manner to the real impacts.

Pressure Wave Caused by Trinitrotoluene (TNT) Underwater Explosion—Short Review

“…The total load duration on the ship's structure is 0.0376 s [34]. [34]. A significant drop in the pressure wave value between the bow and the stern is noticeable.…”

“…• tr-time when the pressure wave reaches the given element of the structure, s • r-distance to given place of the structure, m • co-sound speed in surrounding medium, m/s For example, if 250 kg TNT is detonated, at a depth of 15 m from a distance of 20 m in front of the mine destroyer's bow (206FM project), she will be loaded with a pressure wave of 11 MPa, which decreases along the ship to a value of 3 MPa (Figure 7). The total load duration on the ship's structure is 0.0376 s [34]. [34].…”

“…Figure 7. Propagation of pressure wave along the ship, detonation of 250 kg of TNT at a distance of 20 m in front of the ship, at a depth of 15 m[34]. A significant drop in the pressure wave value between the bow and the stern is noticeable.…”

Estimating the Size of a Crater after an Underwater Explosion

“…The analysis of an underwater explosion requires taking into account many factors, such as the course of the detonation, physical properties of the environment, detonation wave movement, energy dissipation, movement and pulsation of the gas bubble, reflections of the shock wave from the bottom and surface, movement of the sea bottom, interference of incident and reflected waves, cavitation phenomena and many other factors. An underwater explosion is accompanied by a rapid increase in pressure in its environment, and the initial pressure depends on the type of explosive [8,[17][18][19][20][21][22][23][24][25][26].…”