Development of experimental evaluation method for nonlinear mechanical modeling considering damage in fiber reinforced composites

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03848
• 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: Tokyo University of Science
• Principal Investigator: Ogihara Shinji 東京理科大学, 理工学部機械工学科, 教授 (70266906)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 炭素繊維強化プラスチック / 粘塑性 / 応力緩和 / 非弾性力学挙動 / 積層構造 / 損傷 / ひずみ速度依存性

Outline of Final Research Achievements

Experimental evaluation of monotonic tension at different strain rates, stress relaxation test with increasing strain, loading-unloading test, stress relaxation test during loading-unloading process and ratcheting behavior during loading-unloading test at constant stress range are conducted. Based on the experimental results, orthotropic viscoplasticity model with overstress is developed. The model assumes additive decomposition of total stress into equilibrium stress and overstress and constitutive laws for each stress. Hoffman elastoplastic model is used for equilibrium stress and a model which considers nonlinear dependence on strain rate is used for overstress.

Free Research Field

機械材料・材料力学，複合材料工学，航空宇宙材料工学

Academic Significance and Societal Importance of the Research Achievements

連続繊維強化複合材料・構造の力学挙動モデル化については，微小弾性変形を仮定するものがほとんどで，塑性力学的研究は少なく，特に有限変形を考慮した粘塑性解析はほとんどなされていない．積層構造によっては，そのようなモデル化が必要であり，異方性を有する繊維強化複合材料・構造に対して，損傷を考慮した有限変形下での非線形力学モデルを構築しようとするところに本研究の学術的および社会的意義がある．