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.