Yield Criterion Based on the Mean Function of Tresca and Twin Shear Stress Yield Functions

In order to linearize Mises yield criterion, Tresca and Twin shear stress yield functions were added and their mean function was calculated and used as a new linear yield criterion called MY (mean yield)criterion in Haigh Westergard stress space. The mathematical relationship of the MY criterion and its yield locus in the π plane as well as the derivation of the rate of plastic work done per unit volume were given out. Precision analysis and an actual example show that the MY criterion is a linear one whose maximum relative error with the Mises criterion is no more than 3 9% and mean relative error no more than 1 95%; the expression of plastic work rate done per unit volume for the criterion is also linear.