A modern approach to principal stresses and strains

摘要

A simple formal method of evaluating principal stresses and directions using eigenvalues and eigenvectors of the stress matrix is presented. The method is equally applicable to 2–d and 3–d stress systems and does much to eliminate any risk of undetected errors in calculation or mistakes in assigning a principal stress to its corresponding direction. The method is extended to analysis of the 45d̀strain gauge ros