ISSN: 0090-3973
Page Count: 5

Performance of Chevron-Notch Short Bar Specimen in Determining the Fracture Toughness of Silicon Nitride and Aluminum Oxide
Munz, D
National Research Council senior research associate, German Aerospace Research Establishment (DFVLR),

Bubsey, RT
Materials research engineer and head, National Aeronautics and Space Administration, Lewis Research Center, Strength of Materials Section, Ohio

Shannon, JL

Abstract

Ease of preparation and testing are advantages unique to the chevron-notch specimen used for the determination of the plane strain fracture toughness of extremely brittle materials. During testing, a crack develops at the notch tip and extends stably as the load is increased. For a given specimen and notch configuration, maximum load always occurs at the same relative crack length independent of the material. Fracture toughness is determined from the maximum load with no need for crack length measurement. Chevron notch acuity is relatively unimportant since a crack is produced during specimen loading. In this paper, the authors use their previously determined stress intensity factor relationship for the chevron-notch short bar specimen to examine the performance of that specimen in determining the plane strain fracture toughness of silicon nitride and aluminum oxide.

Keywords:
fracture strength, toughness, brittleness, short bar specimen, chevron-notch short bar specimen, crack toughness, ceramics

Paper ID: JTE10605J
DOI: 10.1520/JTE10605J
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