COMPARISON OF YIELD STRENGTH THEORIES WITH EXPERIMENTAL RESULTS

On the basis of the testing data of the yield strength of various types of plastic metals under biaxial and triaxial combined tensile-compressive principal stress, the relative errors calculated using Tresca strength theory, Mises strength theory, Mohr-Coulomb strength criterion, Beltrami's maximum energy theory and limiting strain energy strength theory (LSEST) are analyzed, respectively. The result shows that the errors according to LSEST are within 10%, being the minimum. The errors calculated by Tresca strength theory, Mises strength theory and Mohr-Coulomb strength criterion are -36%, -27% and -23%, respectively. The calculating results are on the conservative side compared with the test ones. For materials with equal tensile and compressive yield strength, Tresca strength theory and Mises strength theory could not be applied either, and the theoretical shear yield strength is times of the tensile yield strength. LSEST could be used to calculate the strength under biaxial and triaxial combined tensile-compressive principal stress, which is consistent with Rankine strength theory under a full tensile and a full compressive principal stress state, which suggests that LSEST has a prospect and value for engineering applications.