STUDY OF WATER FLOW EFFECT ON RESPONSE OF PLATES SUBJECTED TO UNDER WATER EXPLOSION

Plates and thin walled structures are generally main elements that are used for fabricating of shell-plating of marine and submarine vessels. As being must exterior parts of vessels that are in contact with water they are prone to various threats that under water explosion is one of main dangerous and unavoidable ones. Extensive studies concerning this phenomenon are available [1], [2], [3]. Various methods are employed for investigation of plate responses subjected to under water explosion (UNDEX). Due to its inherent complexity of problem returns to interaction of fluid and structure (FSI), analytical solutions are very limited and deviations from experiment are considerable. In other hand experimental studies are really expensive and dangerous while their fulfillments require extensive substructures that are not available in every research center. In recent years by development of powerful computer codes are named hydrocodes in particular for handling of high rate mechanics problems, numerical methods approved their capabilities in study of this research area. To the best knowledge of authors all of works devoted to this research field are concerning that the fluid (Water) is calm and in stand situation before detonation of explosive charge and a published study with flowing water effect on the UNDEX phenomenon and its interaction with structure cannot be found. In this paper, using powerful and professional hydrocode ANSYS-AUTODYN, effect of water flow on UNDEX response of rectangular plates is considered. Flow is in tangential direction of plates and velocity of current is in a feasible order to cover regular ocean streams and marine moving objects [4]. High fidelity numerical studies illustrate that effect of flow on distribution of UNDEX overpressure are tangible and maximum deflection of plates may be affected by this phenomenon.