Design of mechanical properties of core structures based on science of origami

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03755
• 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: Meiji University
• Principal Investigator: Ishida Sachiko 明治大学, 理工学部, 専任准教授 (40636502)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: コア構造 / 複合材 / メタマテリアル / 塑性変形 / 折紙

Outline of Final Research Achievements

Honeycomb cores are widely used as lightweight-yet-strong structures. However, such high mechanical properties can be obtained only to the out-of-plane direction, and the high energy absorption capability can not be expected as the uniform configuration of regular hexagons yields progressive buckling deformation at a given load. In this study, we designed new honeycomb cores consisting of a combination of regular hexagons with squares, inspired by structures observed on the outer shells in beetles. The out-of-plane strength, plateau stress, and energy absorption of the new bio-inspired honeycomb cores were equivalent or higher than those of the hexagonal honeycomb cores. In addition, we developed an experimental method using a crank-slider mechanism to measure circumferential sharing stiffness of cylindrical honeycomb cores designed for supporting radial load, and clarified the quantitative relations between the circumferential sharing stiffness and the honeycomb configuration.

Free Research Field

設計工学　折紙工学

Academic Significance and Societal Importance of the Research Achievements

構造の軽量高強度化は，輸送機器や産業機械等の燃費の向上，建築物等においても資源の大幅な節約，ごみの削減につながる．本研究の甲虫の外殻に見られる形状を取り入れた新ハニカムコアは従来のハニカムコアと同等あるいはそれよりも高い機械的特性を有することから，従来のハニカムコアに置き換えることにより，持続可能な社会の実現へと貢献できる．
本研究の甲虫の外殻に見られる形状を取り入れた新ハニカムコアおよび円筒ハニカムコアはいずれもハニカムコアの産業的製造手法で製造できるように設計されている．研究段階から学術的知見を産業へ技術移転することを視野に入れており，大量生産可能な形状であることは産業的に価値が高い．