Structural vibration damping via piezoelectric shunt circuits has received a great deal of attention recently as they are light, easy to use and provide for good vibration damping performance. This study investigates vibration damping of a clamped-free beam under harmonic excitations in the steady state. The damping control strategy utilises the piezoelectric properties of PZT materials and a shunt circuit consisting of series RLC elements in parallel configuration. The analysis was made for the first mode frequency and, at the same time, for the four resonance frequencies.

In vibration control with piezoceramics, a high coupling of the piezoelement with the structure is desired. A high coupling improves the damping performance of passive techniques like shunt damping. The coupling can be influenced by a the material properties of the piezoceramics, but also by the placement within the structure and the size of the transducer. Detailed knowlegde about the vibration behavior of the structure is required for this. This paper presents an in-depth analysis of the optimal shape of piezoelectric elements. General results for one-dimensional, but inhomogeneos strain distribution are provided. These results are applied to the case of a longitudinal transducer and a bending bimorph. It is obtained that for maximum coupling, only a certain fracture of the volume should be made of piezoelectric material&