直接荷重解析法によるLNG船の全船解析

摘要

荷重計算と構造解析を一貫して行う、いわゆる「荷重構造 一貫解析」は船体強度の信頼性と経済性の両立において有益 なツールである。国内では1970年代からSRによる共同研究 に始まり継続的に研究開発が行われているが、特に倉本ら離 散化解析法を用いてサイドロンジの応力シミュレーション を実施し疲労損傷を解明した事例は荷重応力一貫解析の 有用性を実証するものである。%In this paper, structural analysis with Direct Loading Analysis Method (DILAM) and Design Irregular Wave meth6xT(DTW) has been carried out for a 135,000 m~3 LNG carrier and compared with full scale measurement. DILAM is a structural analysis method proposed by author, where wave load from ship motion analysis is applied directly to FE model through interface system. DILAM is especially effective when it is combined with DIW proposed by Fukasawa. The author proposes a procedure with DILAM and DIW and consideration of non-linearity of wave load and compared the results with full scale measurement in Japan-PG trading route. The results of the proposed analysis method generally agree with the measurement. Especially, it is concluded that setting of DIW, for example limitation of maximum steepness of the design wave and introduction of non-linear effect of wave load, are important for rational estimation of maximum stress of ship structure.