Characterization of glass fiber reinforced polymer via Digital Volume Correlation: Quantification of strain activity and damage growth

Strain and damage distributions within a dogbone specimen containing a rectangular notch were assessed in-situ via X-Ray Computer Tomography coupled with Digital Volume Correlation. The specimen cut from a continuous glass fiber mat reinforced polyester resin composite plate was subjected to cyclic tensile loading. The strain-damage interplay was evaluated by analyzing major eigen strain and correlation residual fields. The horizontal strained band emanating from the notch root was present from the beginning of loading. The final failure proceeded along this strained band. The first cracks did not initiate in the notched region, despite high strain gradients. Strain activity and damage growth were quantified by analyzing the cumulative probabilities of major eigen strains. The comparison was made between the notched region and the remaining part of the inspected specimen. It is shown that, although the mean levels were higher in the notched region, the standard deviations of the major eigen strain distributions were higher in the remaining part of the specimen.