Investigation into dynamic progressive collapse behavior of hull girders in waves using hydro-elastoplastic approaches

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15219
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 24020:Marine engineering-related
• Research Institution: Osaka University
• Principal Investigator: Tatsmi Akira 大阪大学, 工学研究科, 助教 (60736487)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 流力弾塑性 / 縦曲げ崩壊 / 崩壊後挙動 / FE/Smith法 / 弾性相似模型 / リスク評価

Outline of Final Research Achievements

When wave load exceeds hull-girder ultimate strength in extreme sea states, hull-girder bending collapse is occurred. To perform a risk assessment for the hull-girder collapse, a hydro-elastoplastic analysis which can consider fluid-structure interaction in post-collapse regime is needed. Therefore, a practical method to analyze dynamic progressive collapse behaviors/response of the hull girder have been developed. In the proposed method, Smith’s method is incorporated with beam finite element method while hydro-dynamic load is estimated based on strip theory. The proposed method has been validated through comparisons with an experiment of a scale model ship in a towing tank and more detailed numerical simulation. After the validation work, the proposed method was applied to a real ship, and important findings about the dynamic progressive collapse response of the hull girder in waves have been obtained.

Free Research Field

船舶海洋工学

Academic Significance and Societal Importance of the Research Achievements

スミス法に従って船体断面の逐次崩壊を考慮しつつ，波浪中における船体全体の動的崩壊応答を解析できる流力弾塑性手法を開発した点で新規性が高い．また，提案手法は汎用のPCであっても数分程度で波浪中の動的逐次崩壊の解析を行うことができ，実用性も高いと考える．提案手法は，作用荷重が船体の縦曲げ最終強度を超過した場合のリスク評価を行うにあたって，非常に有用な解析ツールとなるであろう．