Effect of Micromechanical Stress Cocentrations on Strength of Porous Glass

Abstract

The effect of micromechanical stress concentrations around elastic discontinuities in a glass was investigated. Specimens of glass containing porosity of controlled size and volume fraction were fabricated by vacuum hot‐pressing and strength was tested under uniaxial and biaxial stress conditions. Results were interpreted as a function of the relative sizes of Griffith flaws and the volume of material over which stress concentrations act. For the glass investigated, assuming an adequate flaw density, the strength was dependent on pore size and volume fraction as well as on the loading conditions. It is suggested that differences in uniaxial and biaxial strength are due to differences in stress concentration geometry.