Novel morphing structures show high potential in various engineering applications where shape adaptivity is deemed essential to achieve the optimum functionality under a wide range of operational conditions. Shape memory alloys have been selected as the main actuation elements in a large number of research projects. However, the successful design and realization of a morphing concept is highly dependent on the accuracy of the available modeling tools that provide essential information on the response of both the actuator itself and the whole structure. To this end, a three dimensional, thermodynamically consistent constitutive model that has been recently extended with a modified hardening function to account for partial transformation behavior is adopted to simulate SMA response. The design of a morphing strip system with a SMA ribbon actuator is presented and discussed, while its response is predicted when the effect of partial transformation is taken into account or omitted.