On micromechanical parameter identification and the role of kinematic boundary conditions

Integrated Digital Image Correlation (IDIC) necessitates a mechanical model with appropriate boundary conditions, geometry, and constitutive laws. Because boundary conditions are applied on the entire specimen, they by definition lie outside the employed field of view in micromechanical parameter identification. To avoid excessive computational cost by modelling the entire specimen, Microstructural Volume Element (MVE) is used instead in IDIC, which requires micromechanical kinematic boundary conditions. The aim of this contribution is to examine the influence of errors in boundary conditions prescribed to MVE on the accuracy of micromechanical parameter identification in IDIC. It is shown that relatively small errors in micromechanical boundary conditions may yield significant inaccuracies in the identified material parameters, and that all microstructural features need to be captured.