Evaluating water ingress in glass fiber plastic/Nomex honeycomb panels under varying panel orientation

The paper presents the results of experimental and numerical investigations on water ingress trapped in aircraft honeycomb panels. The ingress of atmospheric water during aircraft service may cause minor or major damages of airplane crucial components. The percentage of water/ice filling honeycomb cells is an important factor related to possible cell damage. This study is focused on the analysis of the following inspection parameters: 1) influence of panel orientation (horizontal, vertical and Inclined at 30, 45 and 60°) on the efficiency of water detection, 2) efficiency and optimization of a heating technique in evaluating water ingress, 3) influence of water/ice phase transformation on detectability of water ingress. The numerical analysis was conducted by using the ThermoCalc-3D software in order to evaluate the detectability of water ingress in the cases where a test panel is placed in different spatial orientations. The samples with water and ice were tested and analysed by using several data processing algorithms available in the ThermoFit software to enhance water detection performance. The signal-to-noise ratio concept was used to compare efficiency of image processing algorithms in the inspection of water ingress in honeycomb panels with varying water content, spatial orientation and water/ice phase transformation.