Research On The Structural Response For Box-girder Hull To Underwater Explosion

In the research of ship vitality, the resistance performance of hull structures tounderwater explosion has always been a priority research area for world’s navies. As a newtype of deck structure, the box-girder has not been studied systematacially and synthetically,especially on the resistance to underwater explosions, which therefore is the main emphasisof this paper. There are three parts on different underwater explosion conditions in thispaper; far-field–considering the shock environment of the structure and equipment;near-field–considering the impact destruction of local structure and the movement-damageof the hull; near field and contact–considering the residual strength of the damaged ship.The following work has been carried out accordingly.Firstly, the former works on box-girder resistance of underwater explosion have beensummarized to guide the present study, and the unique feature in this paper has been pointout. The numerical simulations models of box-girder hull and equivalent hull has beenestablished. Sound solid coupling method is used to solve non-contact explosion problems,and ALE (arbitrary lagrange euler) method is for contact explode.Secondly, the numerical simulations of the underwater explosion with large, mediumand small blast distances have been conducted. The impact response of the box-girder hulland its inner structures has been analyzed; The plastic failure mode of the local structure inthe shock wave stage, and its overall damage caused by the whip movement of the hull inthe bubble pulsation stage have been checked; And the remaining strength of the hull withbreaches has been examined.Finally, the rules and characteristics of structural response, like the displacement,velocity, acceleration, Mises, equivalent plastic strain (PEEQ) and the section moment, inthe typical position of the equivalent original hull compared with the hull with differentforms of box-girder in various specific conditions have been analyzed. Draw conclusionsfrom four different forms of hull structure impact conditions, impact damage, whipmovement and the residual strength properties.