On the use of Flat Piezoceramic Actuator Devices in combination with Modal Structural Models of Light Weight Structures for Vibration Suppression

Abstract

In light weight structures buildt from composite fibre materials, unwanted vibrations due to low structural damping yield a common source of limitations for different applications. For acoustic applications e.g. in aircrafts, noise limits have to be fulfilled. To shorten cycle times in assembly tasks of highly accelerated light weight robot structures, a reduction of these vibrations can also be essential. This can be achieved by increasing the structural damping significantly due to suitable control algorithms, which use piezoceramic patches as structural actuators and sensors. The rigid subcomponents of a structure under consideration can be augmented with flat actuator devices. To model such a plant as input for establishing control algorithms, a fully coupled system can be sol-ved in suitable finite element (FE) software systems, but there are severe drawbacks if the optimi-zation of the actuator locations for enhanced control performance is neccessary. This paper discusses a so-called modal correction method to rapidly fasten the model creation if actuator locations are changed. The underlying method needs a modal decomposition of the passive structure and corrects modal stiffness and mass contributions in combination with the electromechanical coupling of the devices. This is done outside the original FE environment in a matrix orientated software package by using a new electromechanical triangle element, which is applied at the current locations of the piezoceramic devices on exported parts of the structural element mesh.