Research On Optimization Of Structure Form Of Defensive Longitudinal Bulkhead At Broadside Of The Large Surface Warship

The broadside defensive structures of the larger surface warship are the main barrier to defense the anti-ship missiles and other weapons, which play an important role to protect the vitality of the larger surface warship. While as the last defense line of passive protection, the defensive longitudinal bulkhead structure at the broadside plays a vital role, which may suffer not only the penetration of lots of the residual fragments, but also the residual shock wave loading. Therefore the anti-bullet and anti-shockwave performance of the defensive longitudinal bulkhead become important indexes to evaluate the safety of the warship. So basing on the requirement of designing the defensive structures of the warship, the design of the defensive bulkhead structure at the broadside of the warship subjected to the residual fragments and the shock wave has an important engineering significance.In view of the important role of the defensive bulkhead, the following work is carried out in this paper:(1) The numerical simulation of a fragment penetrating different thicknesses of the single plate is carried out. And the penetration progress is compared with the existing experiment, the results show that the penetration progress is similar, which verify the reliability and validity of numerical method of the fragment penetrating the plate. When the initial velocity of the fragment is the same, the relationship of the residual velocity of the fragment and the thickness of the plate is obtained. And when the thickness of the plate is constant, the relationship of the initial velocity and the residual velocity of the fragment are analyzed.(2) The comparison of the fragment penetrating the single plate, the steel/ceramic/steel compound target and the corrugated plate is carried out. The results show that when the surface density is the same, the results show that the residual velocities of the fragment penetrating the corrugated plate are the minimum, then the steel/ceramic/steel compound target; which is to say that the anti-bullet performance of the corrugated plate is superior to that of the steel/ceramic/steel compound target and single plate. (3) The residual velocity and the limit velocity formulas of the cylindrical fragment penetrating the single plate and the steel/ceramic/steel compound target are deduced by energy conservation.(4) The response of different thicknesses plates subjected to the same explosive and the same distance to the explosion center is simulated. The results show that the effect of absorbed energy of the single is the best, and then the corrugated plate, the last is the compound target. But the peak velocity and the peak deflection of the single plate is significantly larger than that of the corrugated plate and the ceramic compound target. The peak velocity of the single plate is almost 100 times of that of the corrugated plate and the compound target.(5) Comprehensive consideration on the role of the defensive bulkhead-anti-bullet and anti-shockwave, the corrugated plate is proposed to be the structure of the defensive bulkhead, and the core plate is not welded on the rear plate.