Analysis Of Integral Destroy Of The Tremendous Unsymmetrical Floating Structure

It has been studied and discussed that the bending-twisting coupling dynamic property of tremendous unsymmetrical floating structure, the transitory response subjected to explosive loading and the transitory capsizing probability, the transitory capsizing probability of damaged floating structure in hauling voyage time in this paper. The effect of added mass has been analyzed on the dynamic property of floating structure. The transitory response has been gotten of floating structure subjected to explosive loading. The large-amplitude rolling random differential equation has been founded of floating structure subjected to wind-wave and explosive loading. The transitory rolling probability density function has been derived of damaged floating structure with initial heel angle subjected to attack of weapon. The transitory capsizing criteria have been founded of floating structure in war-time. The capsizing probability expressions of floating structure at random time have been given in war-time and hauling voyage, and the effect of floating parameter and detonator contents on the capsizing probability has been discussed. The main work contents of this paper are as follows:1. The section bending-twisting parameters of upright and non-upright unsymmetrical floating beam have been solved adopting the thin-walled finite element theory. Assuming that the position and dimension of damage crevasses are determinate and one cabin or some cabins underwater have been damaged and filled with water, the floating parameters of floating beam with macroscopical damage underwater have been calculated adopting the linear Vlasov's floatability theory.2. It has been reasonable that the modifying coefficients of added mass are confirmed with the real shape of structure vibration mode none other than the node amount of vibration mode in traditional method through the comparison and analysis of the effect which the different shapes of vibration mode are on the modifying coefficients of added mass. Considering the effect of added mass on the dynamic property (inherent frequency) of the floating beam for the first time, the comparison and analysis of dynamic property have been conducted considering the added mass, the shearing deflection, rotating inertia, the warping rigidity and the damage degree underwater of the tremendous intact and damaged floating structure adopting the transfer matrix method.3. The calculating model of transitory response has been founded for the tremendous floating structure in war-time, and the kinetic equation considering the coupling effect has been derived subjected to explosive loading with the thin-walled finite element theory. The dynamic response of the tremendous floating structure which sail meeting sea-wave in sea subjected to explosiveloading underwater has been regarded as the fold between the symmetrical response subjected to sea-wave loading and the unsymmetrical response subjected to explosive loading. The heaving and yawning symmetrical response of floating beam subjected to sea-wave loading have been analyzed with two-dimensional hydroelasticity theory. The floating beam is regarded as a changing section Timoshenko beam and the explosive loading is regarded as an impulsive centralized loading. The transitory response of subjected to impulsive centralized loading has been conducted with the vibration mode truncation method considering the effect of added mass on the structure vibration.4. Considering that the tremendous floating structure has been under war environment and lasted transient time, modeling wind and wave excitation as random processes and underwater explosive loading as irregular but determinate action, it has been founded that stochastic differential equation of floating structure which is sailing non-upright .meanwhile nonlinear effect of structure rolling with large amplitude has been taken into account. Combing transient response to external excitations with that to explosion loading, and using maximum entropy to draw the probability density function of combined response, capsizing probability of floating structure under war environment and hauling voyage are derived respectively. Finally, the influence of floating parameter and detonator contents on the capsizing probability has been discussed.5. The FPK equation of the rolling kinetic system of floating structure has been solved with the method that combining the path integral solution which has been perfect in the stochastic structural dynamics field with the order-extension technique, and the transient probability density function of rolling angle of the floating structure with initial heeling angle which is subjected to random external excitation such as wind and wave has been deduced at the attacked moment by weapon. The large-amplitude non-linear rolling motion of damaged floating structure has been forecasted, and the probability density function of rolling angle of has been deduced in time-domain. Moreover, the curve about the effect of the floating coefficients on the capsizing probability has been derived.6. The transitory capsizing criteria of the tremendous floating structure has been founded falling back on the probability density function f{f,t) of thetransitory rolling response, and that is: the tremendous floating structure capsized when the rolling angle exceeded the angle of stability disappearing, (*(*)< #,2^wl>o. The capsizing probability of floating structure has been given at anytime / in war-time and hauling voyage.