Development of a numerical analysis method to reproduce crack opening behavior of closed crack by peening tretment

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20444
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0303:Civil engineering, social systems engineering, safety engineering, disaster prevention engineering, and related fields
• Research Institution: Gifu University
• Principal Investigator: Banno Yuki 岐阜大学, 工学部, 助教 (90966194)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: ピーニング・HFMI / 疲労き裂 / 溶接継手 / 塑性流動

Outline of Final Research Achievements

The goal of this study is to develop a numerical analysis method to reproduce crack opening behavior of closed crack by peening treatment by coupling 3D crack propagation analysis considering plastic flow. To achieve this goal, to clarify the plastic flow acting on the crack surface closed by crack closure retrofit treatment using peening treatment, a cracked welds was peened, and crack surface was closed, and the plastic flow acting on the crack closure surface was observed using a metallurgical microscope. The results showed that a crack was closed by the plastic flow caused in the metallographic structure due to plastic deformation by the crack closure retrofit treatment.

Free Research Field

鋼構造

Academic Significance and Societal Importance of the Research Achievements

本成果は，閉口処理後のき裂面に作用する塑性流動を電子顕微鏡観察により明らかとした．これは，ピーニング・HFMI処理を用いたき裂閉口による延命化手法の信頼性向上に繋がることから，高齢化のよる疲労損傷が著しい我が国の鋼橋の維持管理において社会的意義のある成果であると考える．また，この成果は，き裂閉口メカニズムおよび閉口処理後のき裂の再開口挙動の解明に繋がる学術的意義のある成果と考える．