Multimode Inverse-Analysis Of Residual Strength Of Damaged Ship

Warships face more and more dangerous different anti-ship weapons.The evaluation of warship's life become more and more important.The research of damaged warship's residual strength is one of the main aspects of its life's calculation.In this paper , inverse analysis means has been adopt to calculate the residual strength based on the assumption that the dimension of damaged area and the plastic region of structure have been known and the asymmetrical beam bending theory is applied to set up damaged structural model and the maximum number of different weapons is determined under the condition of verifying and checking the longitudinal strength. According to different damaged condition, the residual strength of the hull under the hogging or sagging bending moments are computed respectively in two cases: One is that the damaged region is above the waterline, the other is that the damaged region is below the waterline. For the first case, the buoyancy is assumed to be unchanged; we determinate the max number of weapon attacked on the warship when the strength isn't satisfied with the criterion that is proposed in the paper. For the second case, based on theory of floodability, the buoyancy is changed,and it results the change of the loading condition and need to calulate the new loads and use te same method to deminate the maximum number of weapons. The ship's strength has been calculated in many aspects such as longitudinal strength,stability ,deflection and so on. The result can be referred by warship structure designers and used to assess the survivability.