Underwater Acoustic Shock Response Of Structures Against Cluster Bombs

Soft killing anti-torpedo weapons based on the underwater acoustic warfare technology emerged for a huge threat posed by new torpedo to ship and submarine. The related structures impulse reponse of underwater acoustic warfare shrapnel studied in this paper is a new topic based on this application background. In order to predict the structural intensity reliability concerned of underwater acoustic confrontation shrapnel under impact loading, this paper is concerned with impact dynamics related are through theoretical analysis, numerical simulation and experimental verification, and then analyses deeply the impact dynamics response characteristics of related structures of projectile.Interior ballistic models of piston-type single and double combustion chamber of underwater acoustic confrontation shrapnel are established to predict the dispersal strutures strength under pressure in the mother bomb bay when the shrapnel is in isolation, and then the cabin pressure are calculated respectively. The impulse response and the strength failure modes of dispersal structure under the pressure of the gas are analyzed using FEM on this basis. Design of improvement for push plate and center bar of single combustion is proposed and it can meet engineering reliability requirements by calculation and analysis.Impact dynamic simulation model of falling projectile has been established by LS-DYNA to meet the requirements of drop crashworthiness and test standards of falling projectile when the underwater acoustic confrontation shrapnel is in the process of transportation, storage and use. Shock response rules of all the components when falling at1.5meter height are emphasized and the uncertainty factors of accidental falls have been considered. Then the influence of drop height, drop gesture, buffer material and fell to the ground to drop impact response of main parts of projectile has been analyzed. Thus, the results will provide the technical reference to the structure optimization design of dispenser, the evaluation of drop reliability and packing technique.Shock response and the rule of the movement in the stage of high-speed water impact of the six-prism flathead submunition have been calculated by numerical methods based on the ALE fluid-structure coupling computation in this paper. The phenomenon when submunition into the water, the impact overload distribution, speed attenuation and shock response of different shells are analyzed. The water entry of common pointed arch and hemisphere head warhead are calculated by the combination with the added mass method to evaluate the influence of head shape of submunition to its water impact. The relationship between the warhead shape and the water entry impact characteristics has been assured qualitatively after analyzing comparatively impact overload and law of motion of the sub-munitions with different head forms. The results shows that the initial velocity of submunition into the water, posture, cavitations and projectile shape etc. have a great influence on its shock response characteristics and law of motion in the water.The research results of this paper have the reference value in the optimization of underwater acoustic confrontation shrapnel related structures and the evaluation of strength reliability.