Subproject B1

The integration of piezo-based sensors and actuators is usually done by pasting the piezo modules onto components, such as sheet metal structures (car roof, driveshaft etc.). Therefore, PZT-ceramics are predominantly used. For an application in sheet metal structures, the Macro Fiber Composites (MFC) – developed by the NASA – seem to be most suitable. They consist of a composite from PZT-ceramic fibers, electrodes and plastics (polymers, usually polyimide). This composition has advantages over monolithic PZT-ceramics in terms of a considerable high degree of efficiency, more flexible construction types and highest fault tolerance.
The subsequent applying of piezo modules has less prospects for a large-scale application. The approach in the project is intent on applying the piezo modules onto a flat sheet metal plate or to integrate piezo modules between two sheet metal plates (piezo-metal-layer-composites) and to realize a forming afterwards. Hence, the following significant problems arise:

• which joining methods are suited for the production of piezo-metal-layer-composites
• which procedure designs qualify joining methods for a subsequent forming
• which deformations do piezo-metal composites tolerate
• which scope for design does exist to reach the desired deformation

The research targets an integration of piezoceramics into sheet metal structures in such a way that in spite of the low formability of the ceramics, the functionality of the piezo sensors and actuators is maintained in a moderate forming process. For that reason, methods for the integration need to be investigated, e.g. adhesive bonding, soldering and mechanical joining. The embedding has to be made so reasonable that a later forming of the piezo-metal composite can be realized to a certain extent. So, e.g. strategies on applying the adhesive, the hardening, the embedding of the piezo module into the adhesive and so on are to be developed. Parallel studies on the stress of these composites are always required and also show the limits of the possible forming.
In the processing of this subproject, a close cooperation with subproject B2 “Simulating the Forming of Piezo-Metal Composites” is necessary.