Electro-mechanical fatigue of CFRP laminates for aircraft applications

The paper focuses on the electro-mechanical fatigue behaviour of CFRP laminates for aircraft applications subjected to DC and AC electrical currents up to 6 A, 900 Hz. Currents are injected into the composite through electrodes produced by 50 gm thick copper electrodepositing at both samples ends. Preliminary tests have been carried out in order to clarify the thermo-electric behaviour of LID and QI composite samples subjected to currents of different type and intensity: a coupled thermo-electric model allows interpreting the result of such tests and helps predicting the temperature fields promoted by such currents. Quasi-static tests have been also run in order to clarify the mechanical behaviour and the failure mechanisms of UD and QI samples subjected to traction loads and to decide the mechanical parameters for the fatigue tests. Finally, instrumented electro-mechanical fatigue tests have been performed on composite samples subjected to electrical currents of several intensities. The fatigue behaviour of the samples can be affected by the injected currents and the number of cycles to failure can decrease for increasing values of the dissipated electrical power, though the damage mechanisms promoted by electro-mechanical fatigue seem to be the same, for both non-electrified and electrified samples. (C) 2015 Elsevier Ltd. All rights reserved.