Wednesday  |  Phipps  |  11:10 AM–11:30 AM

#13894, Validating an Experimental Method to Extract Mode I Cohesive Parameters from Digital Image Correlation Data

Cohesive zones and traction-separation relations are convenient models to represent fracture interface properties, especially at adhesive joints and between composite lamina. However, it can be challenging and time consuming to determine the best cohesive parameters, particularly the separation values at which initiation begins and at which the cohesive element completely fails as well as the shape of the traction-separation relation. Digital image correlation (DIC) allows for high resolution determination of the deformations surrounding the crack tip region. For mode I fracture tests, we use DIC to measure the opening ahead of and at the visible crack tip location and select the point where the opening changes significantly from the baseline as the actual crack tip location. Then we numerically differentiate the energy release rate with respect to the opening at the crack tip as the crack initiates and begins to propagate. To validate this experimental methodology, we apply it to numerical simulations where the cohesive parameters are prescribed.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
SAND2021-13117 A

Kimberley Mac Donald   Sandia National Laboratories
Vincente Pericoli   Sandia National Laboratories
James Foulk, III   Sandia National Laboratories
Brian Werner   Sandia National Laboratories