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Research on the Mechanism of Fatigue Damage in Composite Materials

Research Project

Project/Area Number 04402021
Research Category

Grant-in-Aid for General Scientific Research (A)

Allocation TypeSingle-year Grants
Research Field Aerospace engineering
Research InstitutionKYUSHU UNIVERSITY

Principal Investigator

KUNOO Kazuo  Kyushu University, Engineering, Professor, 工学部, 教授 (90128009)

Co-Investigator(Kenkyū-buntansha) ONO Kousei  Kyushu University, Engineering, Assistant Professor, 工学部, 助手 (90038092)
UDA Nobuhide  Kyushu University, Engineering, Associate Professor, 工学部, 助教授 (20160260)
SAKURAI Akira  Kyushu University, Engineering, Professor, 工学部, 教授 (80037952)
Project Period (FY) 1992 – 1994
Project Status Completed (Fiscal Year 1994)
Budget Amount *help
¥31,400,000 (Direct Cost: ¥31,400,000)
Fiscal Year 1994: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1993: ¥20,500,000 (Direct Cost: ¥20,500,000)
Fiscal Year 1992: ¥8,400,000 (Direct Cost: ¥8,400,000)
KeywordsComposite Materials / Fatigue / Delamination / Acoustic Emission / Failure / Failure Mode / PEEK Matrix / Epoxy Matrix / ひずみ測定
Research Abstract

We developed programs of a personal computer to control a fatigue loading system. The purpose of the program is to avoid reduction of load in the progress of fatigue failure, to measure precisely the stiffness reduction ratio and to pick a replica of a specimen every specified cycle. To cope with a tab failure during a fatigue test, we conducted a finite element analysis of a specimen with a tab and proposed the new tab with urethane foam on a specimen which gave reliable experimental results. The experimental results of 45-degree angle-ply laminates subjected to tension-tension repeated load showed that the stiffneess reduction ratio of epoxy matrix was higher than that of PEEK matrix and the fatigue life of epoxy matrix was much lower than that of PEEK matrix. In the case of [<plus-minus>45]_<4s> specimen of epoxy matrix, crack density in the free-edge region and acoustic emission rate increased after 100 repeated loads. The failure mode of a quasi-isotropic laminate subjected to tension-tension repeated load depended on the difference of matrix and directions of tension load. However in the case of compression-compression repeated load, stacking sequence of a laminate did not deeply affect failure. The stiffness reduction rate versus a number of cycles became low after 30% of fatigue life and was 60% just before fatigue failure. The failure mode of epoxy matrix showed brittleness, but the failure mode of PEEK matrix showed ductility.
We developed a simplified method for determining the strain energy release rate components of free-edge delamination in composite laminates. As that was verified by a finite element analysis, it is very useful to clarify a failure mechanism of fatigue.

Report

(4 results)
  • 1994 Annual Research Report   Final Research Report Summary
  • 1993 Annual Research Report
  • 1992 Annual Research Report

Research Products

(19 results)

All Other

All Publications (19 results)

  • [Publications] K.Kunoo: "Generalized Quasi-Three Dimensional Analysis of Composite Laminates with Unsymmetrically Located Free-Edge Delaminations" Theoretical and Applied Mechanics. 41. 137-146 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] 小野原 薫: "自由縁層間剥離を有する複合材積層板の最終破壊強度" 九州大学工学集報. 66. 173-179 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "Stress Field in Postbuckled Composite Stiffeners Loaded in Compression" Proc.Int.Conf.on Advanced Composite Materials. 315-321 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] K.Kunoo: "Free-Edge Effects of Composite Laminates" Proc.Asian-Paciffic Conf.on Aerospace Technology and Science. 206-211 (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "Postbuckling Analysis of Composite Stiffeners Using Shear Deformation Theory" Proc.Asian-Pacific Conf.on Aerospace Technology and Science. 212-217 (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "A Simplified Method for Determining Mode Components of Strain Energy Release Rate of Free-Edge Delaminations in Composite Laminates" Theoretical and Applied Mechanics. 44. (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "A Simplified Method for Determining the Str ain Energy Release Rate Components of Free-Edge Delaminations in Composite Laminates" The Tenth International Conference on Composite Materials (ICCM-10). 10. (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] K.Kunoo: "Generalized Quasi-Three Dimensional Analysis of Composite Laminates with Unsymmetrically Located Free-Edge Delaminations" Theoretical and Applied Mechanics. vol.41. (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] K.Onohara: "Ultimate Strength of Composite Laminates with Free-Edge Delamination" Technology Reports of Kyushu University. vol.66, No.3. (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "Stree Field in Postbuckled Composite Stiffeners Loaded in Compression" Proc.Int.Conf.on Advanced Composite Materials. (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] K.Kunoo: "Free-Edge Effects of Composite Laminates" Proc.Asian-Pacific Conf.on Aerospace Technology and Science. (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "Postbuckling Analysis of Composite Stiffeners Using Shear Deformation Theory" Proc. Asian-Pacific Conf. on Aerospace Technology and Science. (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "A Slimplified Method for Determining the Strain Energy Release Rate Components of Free-Edge Delaminations in Composite Laminates" The Tenth International Conference on Composite Materials (ICCM-10). (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] N.Uda: "A Simplified Method for Determining Mode Components of Strain Energy Release Rate of Free-Edge Delaminations in Composite Laminates" Theoretical and Applied Mechanics. (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1994 Final Research Report Summary
  • [Publications] K.Kumoo: "Free-Edge Effects of Composite Laminates" Proc.Asian-Pacific Conf.on Aerospace Technology and Science. 206-211 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] N.Uda: "Postbuckling Analysis of Composite Stiffeners Using Shear Deformation Theory" Proc.Asian-Pacific Conf.on Aerospace Technology and Science. 212-217 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] 小野原 薫: "自由縁層間剥離を有する複合材積層板の最終破壊強度" 九州大学工学集報. 66. 173-179 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] N.Uda: "Stress Field in Postbuckled Composite Stiffeners Loaded in Comp-ression" Proc.Int.Conf.on Advanced Composite Materials. 315-321 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] K.Kunoo: "Generalized Quasi-Three Dimensional Analysis of Composite Laminates with Unsymmetrically Located Free-Edge Delaminations" Theoretical and Applied Mechanics. 41. 137-146 (1992)

    • Related Report
      1992 Annual Research Report

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Published: 1992-03-31   Modified: 2016-04-21  

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