Periodical maintenance NDT-based inspections are generally used for almost
all complex technological structures today. The idea of using specific sens
ors integrated in the structure for structural real time monitoring (or hea
lth monitoring) is now in progress. Carbon-fibre-reinforced polymers (CFRP)
are increasingly used as structural parts, especially in the aircraft indu
stry. This work deals with the possibility of detecting in-situ damage in C
FRP by the use of DC or AC electrical property measurements. Monotonic test
s under post-buckling bending conditions are being performed on cross ply [
0/90](s) and [90/0](s) carbon/epoxy laminates. The monitoring of electrical
resistance and capacitance changes, linked to the modifications of the con
duction paths in the composite, and occurrence of voids during loading, all
owed the detection of damage growth. It seems that DC electrical conduction
allows to detect fibre failure, but AC measurements are more suitable for
monitoring matrix cracks (delamination, fibre/matrix debonding or transvers
e cracks). (C) 2001 Elsevier Science Ltd. All rights reserved.