Plastic Deformation

· The cross section of the von Mises yield surface is compared to the Tresca cross section. The view is looking down the hydrostatic line.
· These two models were tested by multi-axial stress experiments on thin walled metal tubes. These measurements combined torsion and tensile loading.
· The Tresca model predicts a value of 2.0 for the ratio of the tensile yield stress to the torsional yield stress. For the von Mises model the value is 1.73.

From: Wyatt & Dew-Hughes, "Metals, Ceramics & Polymers," Cambridge (1974)