Accession Number : ADA314124

Title :   Fracture Toughness Measurements of Two Specimen Geometries Considering Stability in Brittle Materials.

Descriptive Note : Final rept. Apr 94-Sep 95,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Cho, Kyu ; Baratta, Francis I.

PDF Url : ADA314124

Report Date : AUG 1996

Pagination or Media Count : 30

Abstract : It has been shown that a lack of stable crack extension can influence the critical stress intensity factor (SIF) measured for brittle materials. Previously performed stability analyses of two specimen geometries were used to design experiments, which would make it possible to observe the transition from unstable to stable fracture as a function of the specimen compliance. This transition was observed to be in agreement with the predictions. The lack of stability gave higher critical SIF values for the material with the higher fracture toughness, while this difference was lost in the experimental scatter for the other materials.

Descriptors :   *FRACTURE(MECHANICS), *CERAMIC MATERIALS, *CRACK PROPAGATION, STRESS STRAIN RELATIONS, LOAD DISTRIBUTION, STRESS ANALYSIS, CRACKING(FRACTURING), DISPLACEMENT, MODULUS OF ELASTICITY, TOUGHNESS, BENDING, RUPTURE, BRITTLENESS, ALUMINUM OXIDES, GRAIN BOUNDARIES, SILICON NITRIDES, STRESS CONCENTRATION.

Subject Categories : Mechanics
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE