

Multifunctional SMA Reinforced Composites for SHM and De-Icing
Abstract
During the last decade Shape Memory Alloys based composites have attracted the attention of a large number of researchers because of the great benefits that they could provide to traditional laminates in terms of mechanical properties enhancement. Indeed, the research to date has tended to focus more on the structural properties of such systems rather than on the non-structural features that a network of SMA network is able to activate. This work is focused on the study of the SHM/NDT feature of a multifunctional composite obtained embedding a hybrid network of NiTi wires within the structure of a CFRP. The multifunctionality of such materials relies on the possibility to exploit the electro-thermal properties of the SMA to localize potential internal damages within a CFRP laminate, by measuring the variation in the apparent temperature on the composite surface via an in-situ active thermography that does not need external heaters or lamps to generate the thermal stimulation required for the analysis. The sensitivity of this technique was evaluated by testing several hybrid samples with delaminations characterized by increasing severity positioned a different distances from the top surface and at different depths within the laminate. Moreover, the presence an embedded heating source has been also tested as a promising ice protection system for composite aerostructures due to its rapidity and effectiveness.