Underwater blast resistance of double cylindrical shells with circular tube stiffeners

Abstract

Underwater explosion seriously affects the combat performance and vitality of submarines. In order to improve the blast resistance of stiffened double cylindrical shells, a new type of stiffened style that replaces the traditional T-shaped stiffeners with circular tube stiffeners, namely O-shaped stiffeners are studied. A series of comparative underwater explosion tests are carried out on two scaled stiffened double cylindrical shells with O and T-shaped stiffeners. Based on the tests, more detailed numerical simulations are made to explore the influence of the structure parameters on the shock performance of the whole structure. It is shown that the O-shaped stiffeners show more superior crushing performance than T-shaped ones when the large plastic deformation appears on the shells. As the plastic deformation of the T-shaped stiffeners is dominated by harmonic buckling while that of the O-shaped stiffeners is dominated by the flattening deformation of circular tubes, the latter can produce greater plastic deformation and absorb more shock energy to reduce the internal energy of pressure hull and thin hull. The shock response spectrums measuring at pressure hull can also be significantly attenuated at high frequency band. Therefore, the O-shaped stiffeners may be more effective sacrificial connected structures in the submarine.