PROCESSING STUDIES FOR THE DEVELOPMENT OF A ROBUST MANUFACTURE PROCESS FOR ACTIVE COMPOSITE STRUCTURES WITH MATRIX ADAPTED PIEZOCERAMIC MODULES

Active composite structures based on thermoplastic matrix systems exhibit a high application potential for lightweight structures ready for series production, due to the high specific mechanical properties as well as the high design freedom combined with economic and reproducible manufacture processes. Moreover, the integration of additional functional components like material-embedded piezoceramic actuators or sensors in thermoplastic lightweight structures enables a purposeful manipulation of the dynamic and vibroacoustic structural behaviour. Among function integration like quality monitoring or active vibration and noise control, also structural applications for example in morphing structures and compliant mechanisms are possible. Thus fibre-reinforced thermoplastic composites with embedded material adapted piezoceramic modules offer a wide area of new applications. Actually the lack of efficient manufacture processes impeded the spread of these new material systems. The use of adaptive composite structures in series applications requires novel actuators and sensors with related manufacture processes capable for series production. This publication gives a contribution for the development of a robust and efficient manufacture process for such new active composites, which bases on a material and actuator adapted hot pressing technique for the realization of short cycle times. Therefore the main focus is put on experimental and theoretical studies for the integration of piezoceramic elements into fibre-reinforced structures. Besides the evaluation of design and process parameters, the influences of the processing parameters on the ceramic elements are investigated to create an adaptive composite structure without damaging of the brittle ceramic. Basic elements of these studies are new thermoplastic composite compatible piezoceramic modules (TPM), which are predestined for a material homogeneous actuator integration in fibre-reinforced thermoplastic composites by use of a welding process. The investigations show a successful manufacture and embedding of these novel piezoceramic modules into fibre-reinforced structures.