Piezoceramic Honeycomb Actuators

Abstract

The success of active vibration control in adaptronics decisively depends on the performance of the actuators used as multifunctional structural elements. DLR`s concept of impedance matched actuators proposes novel actuators in honeycomb design. The partitions of their hexagonal cells are made of piezoceramic materials. The honeycomb geometry guarantees lightweight properties with nearly perfect load distributions in the plane perpendicular to the cell tubes. Furthermore there is a dynamic flexibility in this plane even when the static stiffness is very high. New fabrication methods are required to realize honeycomb actuators with very small cells, low wall thicknesses and perfect rounded corners. In order to fulfill the lightweight conditions self-organizing effects were used to guarantee optimal 3D geometries. In this context, a local thermal treatment of ceramic structures by employing lasers initiates self-organizing mechanisms via material flow. Experimental comparisons between piezoelectric honeycomb actuators and conventional monolithic actuators demonstrate a reduction of electrical power by a factor of 500. Honeycomb actuators seem to be the most promising candidate for technical applications that require low energy consumption.