Elucidation of mechanical properties in twisted cellulose nanofibers

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22335
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Osaka University
• Principal Investigator: Uetani Kojiro 大阪大学, 産業科学研究所, 助教 (20733306)
• Co-Investigator(Kenkyū-buntansha): 鈴木 望 名古屋大学, 工学研究科, 特任助教 (00779845)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 弾性変形 / 線形性 / 輪郭捻れ / 内部座標捻れ

Outline of Final Research Achievements

In this study, the tensile and bending mechanical tests were conducted using the finite element model of a cellulose nanofiber (CNF) that is sufficiently long to exceed the torsion period, and the effect of the inherent right-handed torsion of natural CNFs on the mechanical performance was clarified. The contribution of both the contour torsion and the internal coordinate torsion was clarified. The final deformation response was found to be determined by the antagonistic effect of both torsional structures. In the tensile test, rotational displacement was suppressed by the internal coordinate torsion, while in the bending test, the contour torsion suppressed deformation in directions other than the loading direction. It is shown that the area moment of inertia of the model with contour torsion is periodically modulated, and the cause of the homogenization of the bendability was clarified.

Free Research Field

木質科学

Academic Significance and Societal Importance of the Research Achievements

本研究は、従来形態解析に留まっていたCNFの捻れが物性に及ぼす影響を解析した。特に、実験的には不可能な、捻れモデルの輪郭捻れと内部座標捻れを分離した解析プロセスにより、計算的手法の利点を最大限活用し、力学変位の不規則性に及ぼす両者の寄与を明確化した。引張および湾曲における弾性変形応答と捻れの関係を明確化することで、構造捻れ成分の異なる寄与が明らかになり、互いに拮抗して変形応答を決定することを導いた。本成果は、捻れたCNFを力学的に精密に活用するための学術的基盤となることが期待される。