On the nonlinear dynamics and flutter response of hybrid shape memory alloy composite beams

Abstract

This study presents a theoretical and numerical investigation of the dynamic response of a hybrid SMA composite beam. Particular emphasis is given to the evaluation of the equivalent damping, the aeroelastic stability, and the possibility to tune the composite’s dynamics by means of pre-strain applied locally to the SMA layers. The model of the hybrid composite beam (HCB) accounts for both the material nonlinearity associated with the phase transformation of the SMA and the geometric nonlinearity (in the von Kármán sense) due to potentially large displacements. The nonlinear governing equations of the HCB are solved by the finite element method and the dynamic behavior of the HCB is assessed for different design parameters, such as thickness, position, and pre-strain level of the SMA layers. Results help understand the role played by the different design parameters in improving the dynamic characteristics of the HCB, with particular attention to effective damping. Furthermore, it is of particular interest to understand the aeroelastic stability of hybrid layered composites due to their widespread applications in aerospace engineering. A simplified model of the nonlinear flutter response of the HCB under supersonic flow conditions is presented and analyzed with particular emphasis on bifurcations and limit cycle oscillations.