Sandwich structures can exhibit several failure modes, depending on specificconfiguration of the structure as well as details of the applied load. One failure mode isdelamination of the face sheet(s) from the core when subjected to Ground-Air-Ground(GAG) pressure cycles. The pressure differential develops with each ascent/descentcycle, causing mechanical stress and potentially face sheet delamination. The likelihoodof delamination is increased if any defect(s) exists in the bondline between face sheetand core. In this study, the GAG cycle was recreated in a controlled laboratoryenvironment. Three panels consisting of Nomex honeycomb core and 3ply, 4ply and8ply face sheets were investigated. It was seen that the bulge created due to pressuredifferential in the 3ply facesheet was higher compared to 8ply facesheet. The out-ofplanedisplacement measured by Digital Image Correlation (DIC) for 3ply, 4ply and8ply face sheets ranged between 0.42-2.46 mm. Moreover, fatigue analysis wasperformed on the three face sheets upto 50th GAG cycles which showed that there wasslight increase in delaminations for the three face sheets after higher number of cycles.This test method proved to be an efficient way to predict delamination growth insandwich panels when subjected to GAG pressurization cycles.
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