Optimal Experimental Measurements of Anisotropic Failure Tensors

Abstract

The resolution of the components of strength tensors derived from experimental data is discussed. It is shown that the variations in the non- interaction components are independent of the tension-compression strength ratios and magnitudes and their relative scatter can be related directly to the scatter in the engineering strength. The variation in the interaction component F₁₂, is dependent on both the magnitude of the biaxial strength and the magnitude of F₁₂; it has no well defined relative scatter and only its absolute resolution can be determined from experi mental scatter. Optimal experiments for F₁₂ using tubular specimens are discussed. Optimal biaxial stress ratios using compression-internal pressure and tension-torsion tests are discussed and experimentally demonstrated.