Testing of the heating element integrated into the honeycomb sandwich structure for active thermography inspection

Abstract

The honeycomb sandwich structures with carbon composite face sheets combined with aluminium or Nomex® honeycomb core are extensively used in the aircraft airframe structure. They provide some key benefits over conventional structures such as increased bending strength and stiffness combined with low weight. However, they show high sensitivity to a certain type of damage, such as object impact, mishandling, etc. Non-destructive inspection methods are needed for a structural health examination. Active infrared thermography is one of them. The quality of the inspection and defect detection depends heavily on the proper application of the external thermal excitation. This paper presents a concept of the sandwich structure with internal excitation by means of an integrated thin-film resistive heating element.