Mechanical behavior of sandwich panels with hybrid face sheets and embedded super-elastic SMA wires under quasi-static loading: An experimental investigation

In this paper the experimental behavior of sandwich panels with hybrid composite face sheets and SMA wires under quasi-static loading test was investigated. The square-shaped sandwich panel was composed of a foam core and hybrid composite face sheets consisted of carbon-epoxy and glass-epoxy laminates, in which pre-strained super-elastic SMA wires were placed between the laminates. Sandwich panels had three types of layouts, with symmetric and asymmetric face sheets and with or without the SMA wires between the layers of the faces of the panel. The panels were subjected to quasi-static loading using the Universal testing machine Zwick 250H. The response of quasi-static loading was presented as force-displacement diagrams for sandwich panels. Moreover, the damage morphology of panels after quasi-static loading test was presented by scanning electron microscope (SEM) and the damaged surfaces of the panels were estimated by active infrared thermography of the damage surface. Through comparing the damage level on the sandwich panels, the effect of the presence of the SMA wires, as well as the symmetry or asymmetry of the panel surfaces in reinforcing the structure and reducing the level of damage caused by quasi-static loading were investigated. The comparison of the behavior of the panels under the quasi-static loading test indicated that the use of SMA wires in the front face and the asymmetry of the surfaces were more effective and reinforced by applying more carbon layers in the back face to increase panel resistance.