Analysis of Partial Fractures on Aircraft Composites Wing

In the stability test of an aircraft composites wing, partial fractures are found in the rivet joint region of the wing skin panel. Besides visual examination, other experimental techniques used for investigation are: crack morphology and fracture characteristics by environmental scanning electron microscopy (ESEM), metallographic observation of cracks and composition analysis of fiber surface by x-ray fluorescence spectrometry (XFS). The results are obtained through the analyses of damage morphology, structure stress and load. Fracture areas of the panel, in which notch effect was formed around the rivet, fractured under alternate compressive load. The wing skin panel fractured at the rivets under compression load. For the inconsistent deformation in the compression process, the damage mode of local areas is shear fracture. The primary cause of the panel fracture is insufficient design strength. However, interface pollution leads to structural strength decline, which induces the fractures occurred.