Dynamic Fracture Toughness of Chevron-notch Ceramic Specimens measured in Split Hopkinson Pressure Bar

  • Lee, Yeon-Soo (Department of Orthopaedic Surgery, VA Healthcare System and University of California in Irvine) ;
  • Yoon, Young-Ki (School of Mechanical & Aerospace Engineering, Seoul National University) ;
  • Yoon, Hi-Seak (School of Automotive Engineering, Chonnam National University)
  • Published : 2002.07.01

Abstract

Measuring dynamic fracture toughness of brittle and small ceramic specimen is very difficult in a SHPB (Split Hopkinson Pressure Bar). As a countermeasure to this difficulty, a dynamic fracture toughness measuring method by the Chevron-notch ceramic specimen was proposed. Tested chevron specimens were of Chevron notch angles of 90$^{\circ}$, 100$^{\circ}$ and 110$^{\circ}$. Through finite element analysis, shape parameters of the Chevron-notch specimens according to notch angles were calculated. And the static fracture tough1ess of the Chevron-notch alumina specimen was measured as 3.8MPa√m similar to that of CT specimen with a precrack. Dynamic fracture toughness was 4.5MPa√m slightly higher than the static one. It was shown in this study that the proposed Chevron-notch specimens are valid to measure dynamic fracture toughness of extremely brittle materials such as ceramic.

Keywords

References

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