**7. Conclusions**

This chapter deals with shunted piezoceramics for vibration damping. A small overview of typical shuntings is presented. Further on, a general model of a one degree of freedom mechanical oscillator with embedded piezoceramics and external electrical circuit is derived.

Based on this system, the optimal tuning of a resonant *LR*-shunt is performed for a damped mechanical system. The influence of the mechanical damping upon the optimal parameters and the resulting damping performance is studied. Further on, a novel combination of a 'SSDI' switching circuit and a negative capacitance is discussed. It is shown that this network inherits the adaptive structure of the SSDI technique and combines it with the enhanced performance of a negative capacitance. An enhanced switching law for bimodal excited systems is presented as well. With this technique, the damping of the main mode can be maximized using the vibration energy stored in the higher mode.

Finally, a squealing disc brake and a bladed disc are introduced as two technical applications for piezoelectric shunt damping. For both cases the vibration behavior is studied by mechanical replacement models, and the location of the piezoceramics and the electrical shuntings are chosen based on these models. In both cases it is possible to control the vibrations and increase significanly the damping of the structure. Measurements are conducted which validate the theoretical models.
