Development of a New Simplified Algorithm for Residual Longitudinal Strength Prediction of Asymmetrically Damaged Ships

Abstract This paper explains the basic theory and a new development of for the residual strength prediction program of the asymmetrically damaged ships, being capable of searching moment-curvature relations considering neutral axis mobility. It is noted that moment plane and neutral axis plane should be separately defined for asymmetric sections. The validity of the new program is verified by comparing moment-curvature curves of 1/3 scaled frigate model where the results from new algorithm well coincide with experimental and nonlinear FEA results for intact condition and with nonlinear FEA results for damaged condition. Applicability of new algorithm is also verified by applying VLCC model to the newly developed program. It is proved that reduction of residual strengths is visually presented using the new algorithm when damage specifications of ABS, DNV and IMO are applied. It is concluded that the new algorithm shows very good performance to produce moment-curvature relations with neutral axis mobility on the asymmetrically damaged ships. It is expected that the new program based on the developed algorithm can largely reduce design period of FE modeling and increase user conveniences.Keywords : Asymmetricity (비대칭성), Collision (충돌), Grounding (좌초), Moment plane (모멘트 평면), Neutral axis plane (중립축 평면), Residual strength(잔류 강도), Iterative-incremental approach (증분 반복법), Average compressive strength (평균 압축 강도)