MATERIAL
Aluminium skins + Aluminium honeycomb sandwich, perfect and defected (as resulting from coin tapping), subjected to compression tests.

SET-UP
Acoustic emission monitoring during step loading (each step 10% of ultimate stress)
(PAC LOCAN-AT AE system)
IR transient thermography monitoring using heating plate (AVIO thermal camera)

RESULTS

Acoustic emission was absent during holding at constant load up to 50% ultimate stress

Thermography during 15 sec. transient after heating for 3 sec. the defects were apparent as areas with different conductivity.

PRESENTED AT AIPnD CONFERENCE (TORINO 1995)