Research On Structure Response Of Warship Under The Attack Of Multiple Weapons

In this dissertation, the finite element method is used to analyze the impulse environment of a surface warship subjected to the attack from double attacks and discuss the laws of the impulse response. The dissertation researches into the following aspects:1. Review the developments and relevant researches in the field of warship's anti-shock performance of our nation and other nations, and then discuss the research actuality of our nation and the anti-shock techniques which need to be developed. Although our nation began to study the underwater explosion not late, the scale and system have not been formed. Especially for warships, the standards of our nation feature to evaluate the anti-shock performance of warships have not come into being. However, as more attention is attached into the anti-shock performance of warships and the research procession is under tougher training, the anti-shock technique of warships in our nation has been promoted by researching into the real ships subjected to underwater explosion.2. Based on the finite element model of the warship, ninty-six cases are set up to calculate its anti-shock performance. Three cases are calculated and analyzed: the warship is subjected to a single attack, double simultaneous attacks and double continuous attacks, including different charge distances, different attack angles and different charge weights. The structural responses are studied along with the charge distances, attack angles and charge weights, and these cases are compared and analyzed.3. When the warship is subjected to the attack from a single charge, the distributions of the impulse responses along the length, along the charge distances, along the angle attacks and along the charge weights are mainly discussed. Results indicate that the impulse response takes on local feature in near-field underwater explosion while it takes on holistic feature in mid-field and far-field underwater explosion. The impulse response of the warship decreases with the increase in the charge distance and varies little with the attack angles although there is only a little increase when the attack angle increases. It becomes greater when the charge weighs heavier, however they are not in linearity.4. When the warship is subjected to double simultaneous attacks and double continuous attacks, the distributions of the impulse responses along the length, along the charge distances, along the angle attacks and along the charge weights are mainly discussed. Results indicate that the distribution of the impulse trends to be uniform in far-field underwater explosion because of the far distance between the two charges. The impulse response decreases with the increase in the charge distance. When the warship is subjected to double simutaneous attacks at stem and midst and when the warship is subjected to such a continuous attacks that the charge at the stem exploded first and the charge at the midist exploded after 0.0.6 seconds, both the velocity and the acceleration at the stem are greater than at other regions. The impulse response is the second greatest when the charge at the midist exploded first and the charge at the stern exploded after 0.06 seconds. The impulse response is the least when the charge at the sternt exploded first and the charge at the stem exploded after 0.06 seconds.5. From the comparison and the analysis, the structural response under double simultaneous attacks is the greatest, and the structural response under double continuous attacks is less. Compared with the sum of structural responses under single charge at different regions, the impulse response under double attacks is less.From the analysis of impulse environment subjected to double attacks, the structural responses along with the charge distances, attack angles and charge weights are given, and the resultes are dealt with non-dimensionally so that it can be used in other warships. This method can offer reference for the design in the anti-shock performance of warships. It is of engineering value in the estimate of the vitality of surface warships.