Zehetner, C: Piezoelectric Compensation

Recently, the interest in active compensation of flexible vibrations in mechanical structures has steadily increased, especially in applications where common methods of vibration suppression are insufficient. Common examples are high precision manufacturing systems, where vibrations restrict accuracy, process speed and lifetime. Active vibration compensation requires the integration of actuators and sensors into the structure, leading to the concept of smart structures and systems which are able to react to influences of the surroundings. The present thesis has been authored at the Institute for Technical Mechanics at the Johannes Kepler University of Linz, where active vibration compensation is a main field of research. The thesis focuses on the shape control of beam-type structures, which are very important and frequently used constructional elements. Main scope is the complete compensation of flexible vibrations by distributed piezoelectric actuation strains, such that the structure behaves like a rigid body. As an extension of the existing literature, a shape control solution is presented for coupled flexural and torsional beam vibrations with super-imposed arbitrary large rigid-body motions. The results of this thesis provide a solid basis for a wide field of future applications.