Preliminary Study On Anti-shock Characteristics Of A Saddle-shaped Bulkhead Sructure

With the great improvement of advanced underwater combat weapons, the shock environment of submarine structures, equipments and staffs is becoming worse. The capability of resistance to explosion shock of a submarine has become an important index of its fighting capability. Therefore, to develop a new type stern pressure bulkhead is a very urgent task to improve the structural capability of resistance to explosion shock, which has significant military and economic values.The saddle-shaped pressure bulkhead is a new type stern pressure bulkhead structure proposed recently. The bulkhead consists of a ring shell, a spherical shell and a strength ring connecting these two shells. In the thesis, numerical investigations on dynamic response of the structure subjected to underwater explosion shock load are carried out by using finite element analysis software ANSYS/LS-DYNA. The effects of major design parameters of the saddle-shaped bulkhead such as the radius of the strength ring and the spherical shell, sectional dimensions of the strength ring, thickness of the ring shell and the spherical shell, thickness ratio of the ring shell and the spherical shell on the dynamic response of such a bulkhead under underwater explosion are analyzed. In the analysis, the effects of azimuth from the saddle-shaped bulkhead and the quantity of explosives on the dynamic response of the saddle-shaped bulkhead are also studied.Numerical results show that the radius of the strength ring has great effect on the dynamic response of the saddle-shaped bulkhead. The capability of anti-shock of the saddle-shaped bulkhead is good when the sectional width and height of the strength ring are almost same. The smaller the radius of the spherical shell is, the better the anti-shock capability of the bulkhead is. However, its influence is limited. Change in thickness of the spherical shell has a certain effect on the anti-shock capability of the spherical shell itself, but has little impact on other structures. Similarly, change in thickness of the ring shell has a certain effect on the anti-shock capability of the ring shell itself and has little impact on other structures. In the case of the same explosion distance, the axial displacement and von mises stress of the measuring points of the structure increase with quantity of explosives alike a parabola.The research work done is helpful to understand anti-shock characteristics of the saddle-shaped pressure bulkhead deeply and has reference values for the design of the saddle-shaped bulkhead structure.