Electronic damping of vibrations in optical structures

Abstract

We have carried out a preliminary experimental demonstration of the feasibility of using external electronic circuits to damp mechanical vibrations in optical systems. The significance of the feasibility demonstration is that substantial levels of vibrational amplitude reduction were obtained with very small transducers in nonoptimal positions on noncritical portions of the optical structure. The prototype optical structure used in the experiment consisted of a membrane mirror stretched over a 25-cm diam glass frame with complex cross section. Five small piezoelectric transducers (19.05 x 3.18 x 0.28 mm) were applied with Duco cement at arbitrary positions on the glass frame. Acoustic excitation was then used to excite the resonances in the optical structure. These vibrational responses were measured, and one particular mode was chosen for the feasibility test. The structure was driven by external vibrations at the resonant frequency of the chosen mode until the membrane response was visible. One transducer as used to sense the vibrations in the frame, and this output was used to drive a negative feedback amplifier that drove one of the other transducers on the frame. With the feedback circuit active between two points on the frame, the vibrational response of the membrane to the external excitation was substantially reduced (7:1).

Implementation of an Electronic Circuit for SSSA Control Approach of a Plate Type Element and Experimental Match with a Feed-Forward Approach

“…In this method, the shunt circuit is only used to change the stiffness of the piezoelectric transducer and thus changing natural frequency of the piezoelectric mechanical damper [14,15]. • Resonant Shunts: they are a more efficient family like single mode R-L or resonant multi-mode shunts [13,[15][16][17][18]. These types of shunts generate an electrical resonance with the piezoelectric capacitance.…”

Tuning of a vibration absorber with shunted piezoelectric transducers

“…An expansion of the R-shunt is the resistive resonant shunt (RL-shunt), which has also been described thoroughly by [6] and was originally introduced by [10]. In this case, an additional inductor is connected to the piezoceramic and the resistor.…”

A Modified Nonlinear Modal Synthesis Scheme for Mistuned Blisks with Synchronized Switch Damping

“…When embedded in or bonded to fundamental structures, piezoelectric materials can convert mechanical energy into electric energy and vice versa. On the basis of this energy conversion capability, a vibration reduction technique is developed [9]. Reference [10] investigated the possibility of dissipating mechanical energy with piezoelectric shunt circuits.…”