Abstract
Background. Shape memory alloys (SMAs) have a unique ability to
recover large pre-strains completely when heated above certain
characteristic temperature called the austenite finish temperature. During
the shape recovery process, a large tensile recovery stress occurs if the
SMA is restrained.
Method of Approach. In this paper, a traditional composite plate
embedded with pre-strained shape memory alloy wires and subject to the
combined effect of aerodynamic and thermal loading is investigated. A
nonlinear finite element model based on the first order shear deformable
plate theory and the von Karman strain-displacement relation is adopted to
study the effectiveness of using SMA fiber embeddings on the flutter
boundary, critical buckling temperature, post-buckling deflection and free
vibration. The aerodynamic pressure is modeled using the quasi-steady
first-order piston theory. The governing equations are obtained using the
principle of virtual work based thermal strain being a cumulative physical
quantity. The Newton-Raphson method is employed to obtain the post-buckling
large deflection, while an Eigen value problem is solved at each temperature
step to predict the free vibration frequencies about the thermally buckled
equilibrium position.
Results. The numerical results show the thermal buckling, free
vibrations, and flutter characteristics of shape memory alloy hybrid
composites, illustrating the effect of the SMA volume fraction and
pre-strain value on the aero-thermo-mechanical response of such plates.
Conclusions. It is found that the higher the volume fraction and
the initial strain of the SMA fiber are, the stiffer the plate is. The
critical temperature is increased and the thermal large deflection is
decreased by using SMA fibers. The critical non-dimensional dynamic pressure
has shown significant increase for the SMA-embedded composite plates.
