Work Groups

The aim of the working group “Forming” is to develop a smart semi-finished part ? with integrated sensor and actuator functions ? and the process required to form it into a structural component. The latter takes place by employing the floating support method for the piezoelectric modules, by means of the initially viscous condition of the adhesive during the forming operation (subproject B1). The adhesive becomes fully cured after the forming process takes place.

In addition to commercially available piezoelectric modules, several internally developed modules will be integrated into the smart part and undergo testing. Such modules are the microstructured piezoelectric modules developed in subproject A2, the thermoplastic-compatible piezoceramic modules (TPM) from subproject A5 and the micro injection moulding piezoelectric modules (µIM) from subproject A6.

The polarisation and the contacting technologies of the modules are developed by the teams of subprojects C3 and A4, respectively. Subproject B2 deals with the numerical investigation of the forming operation including the modelling of the orthotropic structured piezoceramic modules, the floating support effect and the loading of the piezoelectric module.

Modelling of the curing process using an internally developed material model is the focus of subproject C7. Future work includes the integration of this model into the global forming simulation conducted by the team of subproject B2. Studies on the functionality and reliability of the piezo-metal-compounds are performed in the subprojects B1, B2 and C8.

The effects of forming on the polarisation of the integrated piezoelectric modules are investigated in subprojects C3 and C8. Further development of the modules will continue by conducting experiments and numerical simulations. The forming limits under a series of forming conditions and with different types of piezoelectric modules will be determined.

The main research focus of the process chain „fibre-reinforced polymers“ is on the design of active composite structures ready for series production by utilization of thermoplastic-compatible piezoceramic modules (A5, B4) as well as by the direct ma-terial integration of piezoceramic components into polyurethane composites by the novel multi-fibre-injection-technology (B6). Therefore, both current commercially available module designs are material adapted to thermoplastic matrix systems and novel piezoceramic fibre based modules are developed (A5, A1). Beside the question of material compatibility, mainly problems with regard to an integral design of the process chain are investigated. This includes for instance problems concerning the part inherent design of conductors and contacts for the transmission of energy and information (A4, A5, B4).

The verification of the part functionality and the continuous material homogeneous connection of the module components to the composites structure are done by the example of a PT-PIESA uniform plate (C6). By means of the acquired models with respect to the polarization behaviour of piezoceramic materials under temperature and pressure influences, the respectiveness of a thermo-mechanical load on the polarization process can be described and an efficient shifting of the polarization into the part production process (forming and consolidation) can be conducted (C3, B4). In order to proof the integrity and to analyze the state of deterioration of active composite structures, respectively, a non-destructive testing method based on the pyroelectric effect is developed (C8).