<title>Design of passive piezoelectric damping for space structures</title>

Abstract

Passive damping of structural dynamics using piezoceramic electromechanical energy conversion and passive electrical networks is a relatively recent concept with little implementation experience base. This report describes an implementation case study, starting from conceptual design and technique selection, through detailed component design and testing to simulation on the structrure to be damped. About 0.5kg. of piezoelectric material was employed to damp the ASTREX testbed, a 5000kg structure. Emphasis was placed upon designing the damping to enable high bandwidth robust feedback control. Resistive piezoelectric shunting provided the necessary broadband damping. The piezoelectric element was incorporated into a mechanically-tuned vibration absorber in order to concentrate damping into the 30 to 40Hz frequency modes at the rolloff region of the proposed compensator. A prototype of a steel flex-tensional motion amplification device was built and tested. The effective stiffness and damping of the flex-tensional device was experimentally verified. When six of these effective springs are placed in an orthogonal configuration, strain energy is absorbed from all six degrees of freedom of a 90kg. mass.A NASTRAN finite element model of the testbed was modified to include the sixspring damping system. An analytical model was developed for the spring in order to see how the flex-tensional device and piezoelectric dimensions effect the critical stress and strain energy distribution throughout the component. Simulation of the testbed demonstrated the damping levels achievable in the completed system.

Damping by Piezoceramic Devices With Passive Loads

“…The dynamic stiffness in equation (3) is equivalent to the ones relative to models which are commonly used to represent viscoelastic materials: the Zener-Biot model (as also pointed out in [2]) and the Three-Parameter Model. Hereafter, a short description of these mechanical elements is presented.…”

“…The first type of load allows one to model the piezo device as a viscoelastic system, whose dynamic stiffness (complex stiffness) can be written as the Zener-Biot model [2,3], which has been adopted in this paper to analyse the vibrating structures, or as the ThreeParameter Model [3][4][5]. By comparing the stiffness of the viscoelastic models with the one of a piezo device, it is possible to derive the relationships linking the mechanical values with the mechanical and electrical characteristics of the two models.…”

Piezoelectric Transducers for Vibration Control and Damping

“…The text contains numerous examples and experimental results obtained from laboratory-scale apparatus with details of how similar setups can be built. aerospace systems [4,106,43], and more recently they have been critical in advancing research in nanotechnology [26,165,166].…”

“…In future, structures incorporating piezoelectric transducers may form the basis of lightweight, high performance mechanical components for use in space applications [4].…”

A survey of recent innovations in vibration damping and control using shunted piezoelectric transducers

“…Having estimated , or perhaps , the signal produced by the sensori-actuator can now be used for feedback. Several applications for this method have appeared throughout the literature (see, for example, [4], [11], [36], [44], [67], and [73]). In practice, however, there are a number factors that limit the performance of the sensori-actuator, the foremost being the choice of the reference capacitor , that is directly related to the size of piezoelectric capacitance .…”