The Mechanism of Fibrous Structure Constituting Biomaterials and Mechanical Valuations

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 07650093
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Kanazawa University
• Principal Investigator: SHINTAKU Sukenori Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (90019761)
• Co-Investigator(Kenkyū-buntansha): KINARI Toshiyasu Kanazawa University, Faculty of Engineering, Assistant Professor, 工学部, 助教授 (90195321) ; ODA Juhachi Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (30019749)
• Project Period (FY): 1995 – 1997
• Keywords: Biomechanics / Biomaterials / A wisteria vine / An actinidia arguta / A ginkgo nut shell / Material Testing

Research Abstract

When we design a composite material, the structure of plants give us many important hints, because the orientation of fiber structure in plant influence the strength of material. In order to clarify this relation, a wisteria vine, an actinidia arguta and a linden are investigated as materials reinforced in a direction. The phloem fiber of a wisteria vine is almost parallel although is entangled slightly and that of linden is rhombuses meshes. The phloem fiber is most flexible and strong to the rupture in all construction parts of stems. The phloem of an actinidia arguta dose not have the fiber structure and cannot support the load. So it can be bend easily and keep the form after bending.
The phloem fiber of a wisteria vine has the following mechanical properties. In the tensile test and bending test, the breaking stress and Young's modulus decreased with the amount of contained water increases. In spring and autumn it is high Young's modulus and low breaking strength because the orientation of phloem fiber are entangled. The dry xylem of a wisteria vine can be considered as the isotropy material and the stem of it is considered as the composite material whose matrix is surrounded by phloem fiber.
A shell nut shows high strength to the external force. This structure give an important idea to design the materials as an example of the framework. A ginkgo nut shell was investigatesd, and it is clarified that a ginkgo nut shell is composed of cellulose, lignin, slight protein, water and oil, and these constitute the composite material in which cellulose are laminated and pasted by lignin.