Characterization of macro- and micro-deformation behavior in the materials with heterogeneous deformation

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K14608
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Kyoto University
• Principal Investigator: Park Myeong-heom 京都大学, 工学研究科, 助教 (90803479)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 不均一変形 / 局所変形 / ひずみ解析 / デジタル画像相関法 / 局所応力 / 弾性ひずみ / 複相組織

Outline of Final Research Achievements

The present study quantitatively characterized local deformation behavior using the digital image correlation (DIC) technique with ferrite + martensite dual-phase (DP) steels, and the investigation of local stress distribution was attempted by measuring elastic strain through the applied DIC technique. It was found that the greater contribution of martensite to plastic deformation led to a significant increase in its strain-hardening ability. Additionally, the present result also suggests that a subsequent transformation of martensite in the transformation-induced plasticity (TRIP) steels is closely related to the dynamic change in the local stress of martensite.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、デジタル画像相関法を用い負荷中・除荷後の弾性ひずみを測定することで直感的でかつ間便に応力を可視化できる画期的手法を提案している。この成果は材料科学分野のみならず全科学分野において波及力は大きいと考えられる。一方、本提案は間便な応力可視化手法でありながら、除荷時の残留応力を無視していることなど課題点も大いに残っている。こうした課題点に対して本手法は他の残留応力法を組み合わせることで改善すべく更なる工夫をしていく予定である。