جستجوی مقالات مرتبط با کلیدواژه « انفجار زیرآب » در نشریات گروه « مکانیک »

One of the objectives of the present study is to optimize the effective parameters in the free sheet forming process under underwater explosive loading. In the experimental part, in order to investigate the effect of loading type on the maximum permanent deflection and thickness distribution of the plate, blasted-loaded plates due to 12 g and 4 g of explosive charge were used for single loading and repeated loading, respectively. Also, in order to investigate the effect of effective parameters on the process and optimize them, the Coupled Eulerian-Lagrangian method was firstly used for numerical simulation in ABAQUS finite element software. Then, in the optimization section, in order to investigate the simultaneous effect of explosive charge mass at each stage and the standoff distance on the maximum deformation and thickness of the sheet, Design-Expert software and Response Surface Methodology were used. The p-value obtained for the proposed model was less than 0.05, which indicates the significance of the model with a reliability of over 95%. The obtained results showed that the model provided by the software is suitable for this experiment and the values obtained from predicting the model are consistent with the experimental and numerical results. Also, the optimal conditions for the least change in plate thickness and the highest amount of permanent deflection were presented.

The explosion process is a sharp increase in volume and a sudden release of energy, usually accompanied by an increase in temperature and the release of gas. The phenomenon of underwater explosions is different from explosions that occur on the surface of the earth due to the characteristics of water. In the process of explosive forming, the choice of water as an interface due to much higher mechanical impedance of water than air and consequently higher inertia of water, is a more appropriate option. In underwater explosive forming, the wave caused by the explosion is propagated by the water environment in a fraction of a second to the target sample, and after colliding and transferring energy, it causes a very high strain rate in it, which increases and Improves sample deformation. In this study, important parameters in the underwater explosion process such as explosion depth, water depth and water vessel geometry and their impact on underwater explosive forming have been investigated. Also, the purpose of this study is to comprehensively investigate the effective parameters, analytical relationships, background researches and simulations performed in the field of underwater explosive forming.