A novel finite element-assisted approach for damage detection in composite sandwich panels under cyclic loading using thermography

This study develops a novel finite element simulation framework to facilitate thermography-based damage identification in fiber/polymer composite sandwich panels with foam cores under constant amplitude cyclic load. The finite element model predicts surface temperature contours induced by self-heating. The heat generation rate in material points is calculated from viscoelastic energy dissipation in a loading cycle, and the steady-state temperature distribution is predicted by performing a heat transfer analysis. Sandwich panel specimens made of glass/epoxy composite skins and PVC foam core are tested under cyclic load before and after introducing artificial damages with the shape of circular notches. The proposed method identifies the artificially introduced damages as well as fatigue damage initiated in the composite sandwich panels based on temperature contour predictions.