Development of a Ferroelastic Constitutive Model Using Micro-Mesodynamics Coupling and Its Application to SOFC

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K14845
• 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: Keio University
• Principal Investigator: Muramatsu Mayu 慶應義塾大学, 理工学部(矢上), 講師 (20609036)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: SOFC / FEM / MD

Outline of Final Research Achievements

In order to develop a mathematical model that can represent the ferroelastic phenomena in SOFCs considering the microstructural evolution of lanthanum strontium cobalt ferrite (LSCF), which is used as the air electrode of solid oxide fuel cells (SOFCs), molecular dynamics analysis was employed to construct an analytical method and model, and numerical analysis was conducted. The numerical analysis was carried out.
In the deformation process of perovskite LSCFs, intense atom diffusion and reactions accompanying the change from cubic to rhombohedral crystals occur during the development of the band structure, and it is considered that the atom behavior and band structure development respectively induce the stress nonlinearity in ferroelasticity.
In this study, molecular dynamics-mechanics elemental analysis is applied to this problem.

Free Research Field

固体力学

Academic Significance and Societal Importance of the Research Achievements

本研究では，弾性エネルギーを考慮したエネルギー汎関数からフェーズフィールドモデルを導出した．強弾性モデルに基づき単結晶の強弾性解析を行いラメラ構造やヘリンボーン構造など観察される構造が数値解析的にも得られることがわかった．さらに分子動力学シミュレーションを実施し，フェーズフィールドモデルに適応する手法を開発した．また，有限要素解析より分子動力学シミュレーションのモデルに強制変位を与える手法も開発した．得られた分子動力学-有限要素連成シミュレーションの結果積分点毎に分子モデルに異なる変形を与え，一度に一つの要素が受ける変形に関して複数の変形のテストケースを試すことが可能となった．