Thermal buckling suppression of supersonic vehicle surface panels using shape memory alloy

An efficient finite element method for the prediction of critical temperature, postbuckling deflection, and vibration characteristics is presented for traditional composite plates embedded with prestrained shape memory alloy (SMA) wires. The temperature-dependent material properties of SMA and composites and the large deflections are considered in the formulation. An iterative eigensolution is presented to determine the critical temperature, the Newton-Raphson method is employed to obtain postbuckling large deflection, and the eigensolver is used to predict free vibration frequencies about the thermally buckled equilibrium positions. Results show that the critical buckling temperature can be raised high enough and that the postbuckling deflection can be completely suppressed for surface panels of supersonic vehicle applications by the proper selection of SMA volume fraction, prestrain, and alloy composition. Weight savings based on critical temperature in the use of SMA as compared with the traditional composite and titanium plates are demonstrated.