Thermal damage analysis and acoustic emission localisation on honeycomb panels
AIM OF THIS WORK
To appraise the effect of repeated thermal solicitations on sandwich panels through acoustic emission and infrared thermography.
MATERIAL
Panel skins were made with epoxy resin HTA 6376C reinforced with Fibredux carbon fibres; its core was a AEROWEB A1-4S-5 honeycomb. Bonding was obtained through Redux 312 adhesive.
Three series of panels: without defects, with artificial defects and bonded with modified cure cycle.
EXPERIMENTAL PROCEDURE
After heating the panel up to 60ºC using a hot platen, the subsequent cooling down phase was monitored with the combined use of the two NDT techniques, up to the end of temperature transient on the material. The four AE sensors were placed at the four corners of the thermographic observation surface, excluding a 10% edge of the panel surface
COMMENT
Such an experimentation fits particularly well with the combined use of different NDT techniques, able to perform defects recognition and sizing and therefore alternative to divulged methods for sandwich inspection like e.g., mechanical impedance and coin tapping.
