Transformation of embedded shape memory alloy ribbons

Shape memory alloy (SMA) wires can be embedded in a host material to alter the stiffness or modal response and provide vibration control. The interact ion between the embedded SMA and the host material is critical to applicati ons requiring transfer of loads or strain from the wire to the host. Althou gh there has been a significant amount of research dedicated to characteriz ing and modeling the response of SMA alone, little research has focused on the transformation behavior of embedded SMAs. In the current work, photoela sticity was used to quantify the internal stresses induced by the actuation of a thin SMA ribbon in a polymer matrix. Through the use of a CCD camera and a frame grabber, photoelastic fringes were digitally recorded at discre te time increments. The stress contours were then analyzed quantitatively a s a function of time. A numerical simulation of the embedded ribbon was als o carried out using a coupled SMA constitutive model. The thermomechanical model accurately predicted the stress contours throughout the experiment.