Multiaxial Loading Fracture of Al2O3 Tubes: II, Weibull Theory and Analysis

The Weibull statistical fracture theory for multiaxial loading was developed for thick- and thin-walled tube geometries subjected to multiaxial loading in tension-internal pressure, compression-internal pressure, and pure torsion. As compared to uniaxial tension, lower strengths are predicted for tension-tension stress states and higher strengths for tension-compression stress states. Comparison to experimental results for A1203 tubes indicates a reasonable agreement with Weibull theory predictions for tension-internal pressure and compression-internal pressure conditions, but an underestimation of stress state effects in pure torsion. Results indicate a weakening effect of in-flaw-plane tensile stresses, with no observed influence of in-plane compressive stresses.