Stability Analysis Of Warship Structure Attacked By The Conventional Weapons

This article starts with the warship stability, it is analysed that the warship subjects to conventional weapons attack in particular underwater.Consider that the damage of the warship produces sloping after entering water , which make the warship stability reduced ,thus which may lead to warship capsized in the random process as wind and wave.Firstly the floatability of damaged warship changes, the floatation parameters of damaged warship is computed based on the linear theory of floatability; secondly analyzing and calculating the environmental and explosive excitation to the damaged warship, the wind excitation are composed of steady and unsteady wind , and taking the steady wind as the static force on the ship, unsteady wind and wave excitations are considered as stochastic dynamic on the warship, stochastic model of them are described by spectral density function, and the explosive excitation is regarded as determinate but irregular excitation. The paper analyzes two situations, the first : The warship suffers an attack, only considered the broken hull produces the slant of the warship, but neglects the effect of explosive excitation, under this situation establishes the nonlinear differential equation of the damaged warship rolling in the stochastic sea; The second kind of situation: After an attack causes the warship damaged and have the initial lateral heeling, the damaged warship once more suffer the attack, under this situation takes into account the explosive action and buids the nonlinear differential equation of the damaged warship rolling.Finally separately analyzing and solving the two nonlinear differential equations,and gains the period and transient probability density function of the damaged warship rolling, later the existing capsizing criterion is introduced to evaluate the capsizing probability of the periods and transient. Through a simplified model analasys the relationship and law between the damaged ship capsized probability and the damaged cabin position as well as the different sea conditions,which offers reference to improve the survivability of warship and finger the effective site of warship where conventional weapons attack.