Mechanisms of fatigue life extension of CFRP due to nano fibers and development of prepreg using nano fiber modification

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289012
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Doshisha University
• Principal Investigator: Fujii, Toru 同志社大学, 理工学部, 教授 (20156821)
• Co-Investigator(Kenkyū-buntansha): 大窪 和也 同志社大学, 理工学部, 教授 (60319465)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: セルロースナノファイバー / ナノファイバー / 高分子系複合材料 / 炭素繊維 / CFRP / 機械的特性 / 耐久性 / CFRTP

Outline of Final Research Achievements

The fatigue life of CFRP is well improved by modifying the polymer matrix with nano fibers such as Cellulose Nano Fibers due to an increase of observed adhesive strength between carbon fiber (CF) and polymer matrix. When nano fibers (NF) are well dispersed in the matrix, the physical modification of matrix becomes significant while they stick on CF, their effect disappears. NF must be enough longer to slide across two adjacent fibers. If nano fibers stick on the CF surface, the physical modification effect does not happen. Plastic deformation due to nano/micro crazing is induced at NF ends. Stress concentration at the CF/matrix interface becomes low. Then, fatigue life is extended.
UD prepreg was successfully developed using loosed fiber tows. CF-SMC using vinylester was also developed using sub-micron glass fibers whose mechanical properties are greater than those of commercially available CF-SMC. The applicability of nano fibers was also demonstrated using PP matrix for CFRTP.

Free Research Field

複合材料