• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Dynamic fracture initiation criterion in ceramics under combined mode impact loading

Research Project

Project/Area Number 04650066
Research Category

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

Allocation TypeSingle-year Grants
Research Field 機械材料工学
Research InstitutionOsaka University

Principal Investigator

NAKANO Motohiro  Osaka University, Faculty of Engineering, Assoc. Prof., 工学部, 助教授 (40164256)

Co-Investigator(Kenkyū-buntansha) KISHIDA Keizo  Osaka University, Faculty of Engineering, Professor, 工学部, 教授 (00029068)
Project Period (FY) 1992 – 1993
Project Status Completed (Fiscal Year 1993)
Budget Amount *help
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,700,000 (Direct Cost: ¥1,700,000)
KeywordsImpact fracture / Mixed-mode fracture / Ceramics / Fracture toughness / Stress sitensity factor / Fracture criterion / Alumina / Loading rate effect / 衝激破壊試験
Research Abstract

Recent progress in ceramics industries has enabled us to use high performance ceramics for manufacturing components of machinery such as turbines. However, the use of high performance ceramics has required further investigation in dynamic fracture mechanics.
In an ordinary case that an impact load acts on a structure, stress waves obliquely impinge to various cracklike flaws in the structural components. The stress waves produce mixed-made stress states around the crack-tips. Thus the dynamic fracture initiation criterion under combined mode loading has to be made clear for assessments of structural integrity in relation to the impact fracture.
For the accurate evaluation of the dynamic fracture criterion, we have developed a new test method for mixed-mode impact fracture using the centerprecracked disk specimen. The impact fracture tests canbe performed under arbitrary combinations of mode I and II by varying the inclibation angle of the centerprecrack. The dynamic fracture toughness values of mode I and II are determiced form critical dynamic stress intensity factors at fracture initiation. The dynamic stress intensity factors are calculated by superposing the step-response functions with respect to the impact load history measured in the fracture test. The stepresponse fuctions have been obtained from finite element analyzes for the precracked disk specimen. The onset of fracture initiation is detected using the strain gage near the crack-tip.
In the resent research, dynamic and static fracture tests are performed for alumina ceramics and some brittle materials under combined mode loadings. The dynamic results are compared with the quasi-static data obtained in diametralcompression fracture tests, and fitted to a simple empirical eriterion proposed in this study.

Report

(3 results)
  • 1993 Annual Research Report   Final Research Report Summary
  • 1992 Annual Research Report
  • Research Products

    (7 results)

All Other

All Publications (7 results)

  • [Publications] Motohiro Nakano and Keizo Kishida: "Mixed-Mode Impact Fracture Tests Using Center-Notched Disk Specimens" Proceedings of The International Symposium on Impact Engineering. Vol.II. 581-586 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] M.Nakano,K.Kishida,Y.Yamauchi,Y.Sogabe: "Dynamic fracture initiation in brittle materials under combined mode I/II loading" Proc.Int.Conf.on Mech.& Phys.Behav.Mat.under Dynamic Loading. (in print). (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Motohiro Nakano and Keizo Kishida: ""Mixed-Mode Impact Fracture Tests Using Center-Notched Disk Specimens"" Proc. International Symposium on Impact Engineering. Vol. II. 581-586 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Motohiro Nakano, Keizo Kishida, yoshiaki Yamauchi and Yuji Sogade: ""Dynamic Fracture Initiation in Brittle Materials under Combined Mode I/II Loading"" Proc. International Confernce on Mechanical and Physical Behavior of Materials under Dymanic Loading. (in print.). (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Motohiro Nakano and Keizo Kishida: "Mixed-Mode Impact Fracture Tests Using Center-Notched Disk Specimens" Proceedings of The International Symposium on Impact Engineering. Vol.II. 581-586 (1992)

    • Related Report
      1993 Annual Research Report
  • [Publications] M.Nakano,K.Kishida,Y.Yamauchi and Y.Sogabe: "Dynamic Fracture Initiation in Brittle Materials under Combined Mode I/II Loading" Proc.Int.Conf.on Mechanical and Physical Behavior of Materials under Dynamic Loading. in print. (1994)

    • Related Report
      1993 Annual Research Report
  • [Publications] Motohiro Nakano and Keizo Kishida: "Mixed-Mode Impact Fracture Tests Using Center-Notched Disk Specimens" Proceedings of The International Symposium on Impact Engineering. Vol.II. 581-586 (1992)

    • Related Report
      1992 Annual Research Report

URL: 

Published: 1992-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi