Revisit on the analytic formulations of principal stress orientation in fracture mechanics

In fracture mechanics, it is important to understand the fracture parameters, several strides in these studies have resulted in various analytical formulations. In this work, important analytical formulations of stress field data are revisited. Though the interpretation of stress field data is well studied, the possibility of utilizing principal stress orientation in order to estimate fracture parameters have not been properly investigated. This work attempts to shed some light on that possibility by studying the principal stress orientations for fracture problems using different formulations. In this work, only mode-I problems are considered and whole field stress fields are generated for different analytical formulations. The principal stress values and orientations are determined using Eigenvalue and Eigenvector approach and the principal stresses are studied. It is found that the principal stress orientations are insensitive towards the change in stress field parameter in the case of single parameter equation. In the case of multi parameter equations it was found that principal stress orientations have variation with respect to the stress field parameters.