Progressive damage and failure prediction of interlaminar tensile specimen with initial fabrication induced defects
Cui, Xiaodong; Karuppiah, Anand Vijay; Pham, Dinh Chi; Lua, Jim Y.; Saathoff, Caleb; Seneviratne, Waruna P. 2018. Progressive damage and failure prediction of interlaminar tensile specimen with initial fabrication induced defects. 33rd Technical Conference of the American Society for Composites 2018, vol. 4:pp 2289-2302
An automatic solution process to evaluate the effects of fabrication induced defects in composite components is developed. The framework of this approach includes defects extraction from the X-ray computed tomography (CT) scan data, defects mapping into a finite element model, characterization of intra- and inter- ply damage progression and their interaction, and evaluation of the ultimate strength in the presence of fabrication and load induced damage. Initial CT scans are performed along with photomicrographs to determine the location and geometric configuration of voids and ply waviness in an interlaminar tensile (ILT) test specimen. Voids induced initial delamination zones are inserted at ply interfaces. The effects of voids are characterized using a micromechanics model to capture the degradation of initial properties at the ply-level. Two key solution modules are developed and integrated with our Composite Bolted and Bonded Analysis Toolkit for Abaqus (CB2ATA) toolkit to assign initial intra-ply properties in the perturbed local material coordinates resulting from the ply waviness and insert initial delaminations at corresponding ply interfaces. In order to explore the effects of these defects, two analyses are performed for the ILT specimen with and without the observed defects. The predicted load deflection curves and progression of failure patterns are compared with the experimental measurements.