Development and characterization of textile-processable actuators based on shape-memory alloys for adaptive fiber-reinforced plastics

Fiber-reinforced plastics (FRPs) with adaptive properties make lightweight structures feasible that not only possess a high mechanical force absorption but are also able to adapt their mechanical characteristics, such as geometry and rigidity, to external influences. Within the framework of the basic research presented here, new adaptive FRPs are developed on a basis of textile reinforcement semi-finished products integrated with actuators made from shape-memory alloys (SMAs). The realization of adaptive FRPs requires not only knowledge of the material-specific actuatory properties of the functional materials. It also necessitates the development of textile-technical solutions fully exploiting the actuatory potential of the SMAs within the composite. Promising approaches are hybrid yarn structures based on friction spinning technology. In order to reduce the great experimental effort, modeling and simulation of the SMA's material behavior and of the adaptive FRPs' complex composite behavior are carried out by means of finite element methods. It is shown that the developed actuators generate sufficiently high tensions of about 700–800 N/mm2, to bend the FRP specimen up to 45°.