2022 Fiscal Year Final Research Report

Clarification of uncertainty in ultimate strength of ship structure by developing integrated analysis system of construction, strength and reliability

Research Project

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Project/Area Number	20H02375
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 24020:Marine engineering-related
Research Institution	Osaka Metropolitan University (2022) Osaka Prefecture University (2020-2021)
Principal Investigator	Ikushima Kazuki 大阪公立大学, 大学院工学研究科, 准教授 (80734003)
Co-Investigator(Kenkyū-buntansha)	辰巳晃大阪大学, 大学院工学研究科, 助教 (60736487) 藤公博九州大学, 工学研究院, 助教 (80790716) 小森山祐輔国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (90805110)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	船体構造 / 溶接力学解析 / 溶接変形 / 残留応力 / 座屈崩壊 / 最終強度 / 画像計測
Outline of Final Research Achievements	In this research, a large-scale welding mechanics analysis system was developed by introducing domain decomposition method and shell-solid coupling method. Using the developed method, a 2000 million DOFs problem was solved for a trial. An analysis system that integrates the welding mechanics analysis and the ultimate strength analysis was developed. Using the developed analysis system, the influence of welding deformations and residual stresses on the ultimate strength was investigated. As a result, it was found that the ultimate strength varies with these factors. An ultimate strength test of a stiffened panel structure was conducted. The distribution of displacement was measured by the image measurement method during the test. Through the comparison between the measurement and predicted result, it was found that both results are in good agreement. From these investigations, the effect of building process of the structure on the ultimate strength was investigated.
Free Research Field	船舶工学、溶接力学
Academic Significance and Societal Importance of the Research Achievements	本研究では理想化陽解法FEMに基づく溶接力学解析手法に対して領域分割を導入することで、従来手法では難しい2億自由度の熱弾塑性解析を達成した。これにより、超大構造物の建造時の変形の評価につながる可能性がある。また、溶接力学解析と最終強度解析の統合はこれまでになされておらず、これを実施した本研究は今後同分野の基礎となる可能性がある。加えて、本研究では最終強度試験中の変形の画像計測を実施した。これにより、従来計測が難しかった構造崩壊中の変形が分布かつ時系列で計測可能となった。