Numerical And Experimental Study Of Internal Blast Damage In Ship

With the development of anti-ship weapon, anti-ship missile that equipped withsemi-armor-piercing warhead can intrude into the inner space of the cabin and explodein all probability. Considering the complexity of cabin internal explosion, we usually doresearches on it by conducting missile damage tests. Because of the high cost、lowefficiency and limited sample these tests are not widely conducted. So a deepunderstanding of the mechanism of cabin internal explosion can guide the damageexperiments of anti-ship missile and meanwhile support these experiments on thesmall-scale equivalent cabin, thus increase the efficiency and reduce the cost of theexperiment. This dissertation researches on the transmission mechanism of blast loadingand its damage effect on the ship cabin. The academic innovation consists of three parts:Firstly, considering that the ship grillages are mainly made up of stiffened plates,this dissertation makes a numerical simulation on the dynamical responses of stiffenedplates under blast loading with the guidence of theoretical analysis. The differentinfluences on the shock resistance of stiffened plate caused by the different kind ofstiffeners are compared in the simulation. The results show that the plates stiffened byT-shape stiffener have a stronger shock resistance than those by I-style stiffener andboth of them are stronger than the plates without stiffener. Meanwhile this dissertationmakes an analysis on the computing results of different kinds of elements. We can seethat the difference between the result of model based on shell elements and that basedon solid elements can be ignored. While the comparison between the simulation resultsof scaled model and original model prove that the similitude law of blast can be appliedto the researches on the dynamical responses of stiffened plates.Secondly, a research on the production and transmission rule of blast shock-wavein the free air was performed, and theoretical formulas computing the parameters ofshock wave was presented. Different from explosion in free air, internal explosionphenomenon is further more complex because of the reflection of blast wave on theinner surface and the interaction of the reflected waves. The reports of researches oninternal blast loading can be seldom seen. This dissertation performs a theoretical studyon the mechanical effects of internal blast loading and raises an approximate calculatingmethod of it.Thirdly, based on the researches on the damage effect of cabin under internalexplosion, this dissertation designs and completes a small-scale and equivalent shrinkratio experiment. In this process, damage effects on different shrink ratio and cabin ofdifferent kinds are numerically simulated. A comparison between the results ofsimulation and experiment is made. From which we can see that the simulation haserrors to a certain degree, but the damage situation is similar to the experiment. It means that numerical computation can simulate the blast damage effect effectively.