Stability of functionally graded shape memory alloy sandwich panels

The stability of sandwich panels subjected to the simultaneous action of a uniform temperature and a uniaxial compression is considered. At elevated temperatures, the buckling load can be increased by using shape memory alloy (SMA) fibers in resin sleeves embedded within the core, at the midplane of the sandwich panel. The best results are achieved when the spacing of SMA fibers across the panel is nonuniform, i.e. the spacing, which is minimum at the centerline, gradually increases with the approach to the edges (sinusoidal distribution). The effectiveness of SMA fibers increases with temperature due to larger tensile recovery stresses. The example of stability of sandwich panels considered in the paper illustrates that functionally graded SMA composites may present significant advantages in engineering design.