A new thermoelastic model for analysis of shape memory alloy hybrid composites

A constitutive model and a finite element formulation are developed for pre dicting the thermomechanical response of SMA hybrid composite structures su bjected to combined thermal and mechanical loads. The constitutive model is valid for constrained, restrained, or free recovery behavior with appropri ate measurements of basic SMA material properties. The model captures the m aterial nonlinearity of the SMA with temperature and more accurately captur es the mechanics of composites with embedded SMA actuators as compared to o ther recently developed approaches. The constitutive and finite element mod els are amenable to commercial code implementation. The fundamental thermoe lastic behavior of such structures is described in physical terms and relat ed to the governing equations. It is shown that alloy selection is imperati ve for achieving the desired performance with respect to the application en vironment. It is also shown that fundamental efforts to strategically place actuators can produce dramatic performance improvements. Numerical results are shown for glass-epoxy beam specimens with embedded Nitinol actuators. Control of critical buckling temperature, thermal post-buckling deflection, and random response are demonstrated.