船體強度の塑性學的研究

概要

論文の詳細を見る
Normal and shearing stress distribution in ship's structure are obtained theoretically, when ship is subjected to large bending moment and bending stress is over yielding point. And numerical calculations for the standard ship of A type are performed and following results are obtained : (1) When bending moment coefficient C=displacement×length of ship/bending moment reaches to the value of 24.41,upper deck begins to yield. When C=19.77,second deck begins to yield. And generally the buckling of deck plates between beams occurs after yielding of deck plates. (2) When C=19.58,double bottom begins to yield, and this state can be regarded to have relation with the leakage of water of double bottom consisted of riveted plates. (3) After yielding, the neutral axis gradually changes its position with increase of bending moment. (4) With increase of bending moment, plastic domains spread to longitudinal and vertical directions from decks and bottom of midship. And in plastic domain, principal shearing stress lines are all linear and parallel and directed 45°to sheer line. Above mentioned results are obtained by neglection of effects of local stresses (effects of local load and water pressure, etc.). Actually local yielding will begin to yield at somewhat larger value of above mentioned bending moment coefficient.
社団法人日本船舶海洋工学会の論文