Evaluation of Hull Girder Ultimate Strength by Reliability Analysis Using Monitoring Data

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14960
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 24020:Marine engineering-related
• Research Institution: Kyushu University (2021-2022); The University of Tokyo (2020)
• Principal Investigator: Toh Kimihiro 九州大学, 工学研究院, 助教 (80790716)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 船体縦曲げ最終強度 / 信頼性解析 / 構造モニタリング / スミス法 / モンテカルロ法

Outline of Final Research Achievements

Common Structural Rules for Bulk Carriers and Oil Tankers (CSR BC & OT) published by the International Association of Classification Societies (IACS), which came into force in July 2015, evaluates the hull girder ultimate strength uniformly and deterministically by introducing a partial safety factor. In contrast to this evaluation procedure by CSR BC & OT, to discuss the structural strength of ship hulls probabilistically, the effect of the initial imperfection and the plate thickness reduction due to corrosion on the hull girder ultimate strength was investigated based on the reliability analysis in this study. Also, to acquire actual measurement data for conducting more realistic strength evaluations in the future, some trial measurements on actual ship hulls as well as examination of efficient measurement methods or equipment were performed.

Free Research Field

構造強度

Academic Significance and Societal Importance of the Research Achievements

本研究では，船体構造強度評価に関して，現行の確定論的な規則に代わる確率論を用いた検討を実施した．その結果の一例として，初期不整や板厚減耗による構造強度の経年変化を示した．これらは船舶のメンテナンスなどに資する情報となるため，適切かつ有効に利活用できれば船舶の長寿命化に繋がり得る．また本研究で得られた知見を追検討を通じてさらに深めることで，より合理的なアプローチに基づく船体構造強度の評価手法の確立が望まれる．