57. Desirable Features of Processing Dic Data with a Stress Function

Structural and mechanical components often contain holes or notches, thus introducing stress concentrations which can control member integrity. While DIC is an extremely popular experimental technique, there are difficulties in recording quality DIC data at and near edges, rendering it problematic to obtain reliable stress or strain concentration factors. Moreover, traditional displacement-based strain/stress analyses require knowing both in-plane displacements. For linear-elastic isotropic or orthotropic materials, using a stress function enables one to obtain both in-plane displacements, hence complete strains and stresses, from measured information of only one of the two displacement fields. This can be advantageous since it is not uncommon for one or the other of the in-plane displacements to be of inadequate quality and/or extremely small. Analyzing isotropic materials involves real variables while one represents the stress function in complex variables for orthotropic materials.