Development of Statistical Plasticity for Reconstruction of Macroscopic Material Properties Induced by Microscopic Fluctuations

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03745
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Tohoku University
• Principal Investigator: Aoyagi Yoshiteru 東北大学, 工学研究科, 准教授 (70433737)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ゆらぎ / 結晶塑性論 / 統計処理 / 機械学習 / 力学異方性 / 微視的材料組織 / 転位密度 / 結晶方位

Outline of Final Research Achievements

This study proposed a quantitative method to evaluate the crystal orientation to control the “fluctuation” in crystal orientation that causes mechanical anisotropy. The presented method could reproduce the mechanical anisotropy that could not be expressed only by the crystal orientation by giving an appropriate initial dislocation density for each slip system. Furthermore, in this study, machine learning considering “fluctuation” was performed using stress-strain curves and load-displacement curves for 30 different materials as input and output data, and unknown stress-strain curves were predicted from the load-displacement curves. The macroscopic mechanical properties of polycrystalline metals with fluctuating microscopic mechanical properties were successfully predicted.

Free Research Field

計算塑性力学

Academic Significance and Societal Importance of the Research Achievements

局所的に材料を見てしまうと材料の持っている巨視的な性質を見誤る可能性がある．本研究では，材料内に存在する「ゆらぎ」を適切に処理することによって，局所的な微視的材料組織から巨視的な力学特性を予測することに成功した．このような研究は，材料開発において多大なコストがかかる試作や力学特性測定の回数を激減させることができる．本研究成果によって従来の特性を凌駕した新たな材料組織を予測することが数値解析的に可能となるため，材料開発のブレークスルーとなりえる．