Vibration and noise control using shunted piezoelectric transducers: A review

Smart materials and structures have attracted a significant amount of attention for their vibration control potential in engineering applications. Compared to the traditional active technique, shunt damping utilizes an external circuit across the terminals of smart structure based transducers to realize vibration control. Transducers can simultaneously serve as an actuator and a sensor. Such unique advantage offers a great potential for designing sensorless devices to be used in structural vibration control and reduction engineering. The present literature combines piezoelectric shunt damping (PSD) and electromagnetic shunt damping (EMSD), establishes a unified governing equation of PSD and EMSD, and reports the unique vibration control performance of these shunts. The schematic of shunt circuits is given and demonstrated, and some common control principles and equations of these shunts are summarized. Finally, challenges and perspective of the shunt damping technology are discussed, and suggestions made based on the knowledge and experience of the authors.

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Shunt Damping Vibration Control Technology: A Review

In this paper, the current state of the art on shunt piezoelectric systems for noise and vibration control is reviewed. The core idea behind the operation of electronic shunt piezoelectric circuits is based on their capability of transforming the dynamic strain energy of the host structure, i.e. a smart beam or plate, into electric energy, using the properties of the direct piezoelectric phenomenon and sending this energy into the electronic circuit where it can be partially consumed and transformed into heat. For this purpose, transducers which are made by piezoelectric materials are used, since such materials present excellent electromechanical coupling properties, along with very good frequency response. Shunt piezoelectric systems consist of an electric impedance, which in turn consists of a resistance, an inductance or a capacitance in every possible combination. Several types of such systems have been proposed in the literature for noise or vibration control for both single-mode and multi-mode systems. The different types of shunt circuits provide results comparable to other types of control methods, as for example with tuned mass-dampers, with certain viscoelastic materials, etc. As for the hosting structure, several studies on beams and plates connected with shunt circuits have been proposed in recent literature. The optimization of such systems can be performed either on the design and placement of the piezoelectric transducers or on the improvement and fine-tuning of the characteristics of the system, i.e. the values of the resistance, the inductance, the capacitance and so on and so forth. There are several applications of shunt systems including among others, structural noise control, vibration control, application on hard drives, on smart panels etc. Last but not least, shunt circuits can be also used for energy harvesting in order to collect the small amount of energy which is necessary in order to make the system self-sustained.

/pdf/shunt-piezoelectric-systems-for-noise-and-vibration-control-3mbnq46s3i.pdf

Shunt Piezoelectric Systems for Noise and Vibration Control: A Review

The actuator system of a hard disk drive (HDD) is very sensitive to vibration circumstances It is of great importance to study the dynamic characteristics of the actuator system and to control its vibration response Piezoelectric shunt damping is an emerging vibration suppression technique used to control structural vibration In this paper, two methods are proposed to improve vibration damping efficiency of the classical piezoelectric shunt damping system and suppress the vibration of the actuator arm Based on the analysis of the effect of the generalized electromechanical coupling coefficient on the amplitude of the transfer function and damping ratio, the distribution area of the PZT transducer of the shunt damping system is defined as a design variable of topology optimization to maximize the effective area and hence to maximize the converted vibration energy of the actuator arm Moreover, the vibration control efficiency is improved by introducing a negative impedance converter to eliminate the additional loss resistance of the coil inductor of the shunt circuit Then the vibration control experiments for the actuator arm of an HDD are carried out to verify the proposed methods According to the results of FE analysis and modal tests of the actuator system, topology optimization for the PZT transducer is performed on the target modes while the effects of additional stiffness and additional mass of the coupled PZT transducer are also considered The high damping efficiency of this improved piezoelectric shunt damping system is demonstrated by a 323% maximum increment of damping ratio and 2036 dB, 822 dB and 1202 dB reduction for its three modes of vibration, respectively

https://iopscience.iop.org/article/10.1088/0964-1726/18/6/065010/pdf

Vibration suppression of a hard disk driver actuator arm using piezoelectric shunt damping with a topology-optimized PZT transducer

Adaptive structures are characterized by their ability to reversibly modify their response to external mechanical stimuli so as to extend their operational space (i.e. the range of conditions under which they can operate). This feature differentiates adaptive structures from conventional ones, that are designed to maintain their properties invariant over time. Typically, adaptive structures are comprised of a host structure, one or more actuators, sensors to determine the actual state or trajectory of the structure and a control system. The bulk of the research done in this field focuses on the development of new transducing materials and systems to be used in material based actuators. The present work focuses on the development of host structures with variable mechanical properties. The ability to modify the bending stiffness or the damping properties of a structure can be used to increase the functionality of the actuators in active structures or to suppress high amplitude vibrations in passive ones. The suppression of vibrations can be achieved either by shifting the eigenfrequency of the structure, thus avoiding resonance in the case of narrow band excitation (energy rejection) or by introducing a higher level of damping (energy dissipation). The original contribution made by this work lies in the development and description of a structure that has the ability to adaptively modify its behavior based on a change in mechanical properties, rather than thanks to the action of one or more actuators. The change of the structure’s properties is caused by an apparent change of its topology. Very limited literature on the use of electrostatic forces to modify the interaction between the layers of a multi-layer structure and thus its bending stiffness is available. This moderate level of knowledge on the working mechanism of multi-layer structures with variable bending stiffness, warrants the global approach to the discussion of this topic taken in this dissertation. After giving an overview on the current state of the art in variable stiffness structures, this work first describes the working principle at the base of the modification of the mechanical properties of simple structures, then it proceeds to confirming the validity of the description with the help of simple models and experi-

Electrostatic modification of the bending stiffness of adaptive structures

This work proposes a new piezoelectric shunt damping methodology to control the vibration of a computer hard disk drive (HDD) disk-spindle system. The first part of this work (part I) deals with dynamic modeling of the piezoelectric shunted drive, while the second part of this work (part II) covers experimental implementation of the proposed shunt circuits. In the modeling, a target vibration mode which significantly restricts the recording density increment of the drive is determined by analyzing the dynamic characteristics of the conventional drive. This is achieved by undertaking both modal testing and finite element (FE) analysis. In order to effectively suppress the unwanted vibration of the target mode, a piezoelectric bimorph is then designed and integrated to the drive by considering the mode shapes of the target vibration mode. The mechanical impedance of the shunted bimorph is derived from lamination theory and piezoelectric constitutive equations. In this derivation, the electromechanical coupling coefficient of the shunted drive is analytically incorporated with the mechanical impedance. Using the coupling coefficient, the shunt damping performance for the target vibration mode is predicted and evaluated by presenting the displacement transmissibility.

https://iopscience.iop.org/article/10.1088/0964-1726/16/3/039/pdf

S C Lim

Papers

Vibration control of an HDD disk-spindle system utilizing piezoelectric bimorph shunt damping: I. Dynamic analysis and modeling of the shunted drive