Nonlinear Oscillations: Exact Solutions and their Approximations

Considering the number of applications, and the quantity of research conducted over the past few decades, it wouldn't be an overstatement to label the piezoelectric materials as the cream of the crop of the smart materials. Among the various smart materials, the piezoelectric materials have emerged as the most researched material for practical applications. They owe it to a few key factors like low cost, large frequency bandwidth of operation, availability in many forms, and the simplicity offered in handling and implementation. For piezoelectric materials, from an application standpoint, the area of active control of vibration, noise, and flow, stands, alongside energy harvesting, as the most researched field. Over the past three decades, several authors have used piezoelectric materials as sensors and actuators, to (i) actively control structural vibrations, noise and aeroelastic flutter, (ii) actively reduce buffeting, and (iii) regulate the separation of flows. These studies are spread over several engineering disciplines-starting from large space structures, to civil structures, to helicopters and airplanes, to computer hard disk drives. This review is an attempt to concise the progress made in all these fields by exclusively highlighting the application of the piezoelectric material. The research carried out in the past five years, in the areas of modeling, and optimal positioning of piezoelectric actuators/sensors, for active vibration control, are covered. Along with this, investigations into different control algorithms, for the piezoelectric based active vibration control, are also reviewed. Studies reporting the use of piezoelectric modal filtering and self sensing actuators, for active vibration control, are also surveyed. Additionally, research on semi-active vibration control techniques like the synchronized switched damping (on elements like resistor, inductor, voltage source, negative capacitor) has also been covered

https://iopscience.iop.org/article/10.1088/1361-665X/ab7541/pdf

Review on the use of piezoelectric materials for active vibration, noise, and flow control

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/rpg2.12119

Piezoelectric energy harvester converting wind aerodynamic energy into electrical energy for microelectronic application

With the breadth of applications and analysis performed over the last few decades, it would not be an exaggeration to call piezoelectric materials “the top of the crop” of smart materials. Piezoelectric materials have emerged as the most researched materials for practical applications among the numerous smart materials. They owe it to a few main reasons, including low cost, high bandwidth of service, availability in a variety of formats, and ease of handling and execution. Several authors have used piezoelectric materials as sensors and actuators to effectively control structural vibrations, noise, and active control, as well as for structural health monitoring, over the last three decades. These studies cover a wide range of engineering disciplines, from vast space systems to aerospace, automotive, civil, and biomedical engineering. Therefore, in this review, a study has been reported on piezoelectric materials and their advantages in engineering fields with fundamental modeling and applications. Next, the new approaches and hypotheses suggested by different scholars are also explored for control/repair methods and the structural health monitoring of engineering structures. Lastly, the challenges and opportunities has been discussed based on the exhaustive literature studies for future work. As a result, this review can serve as a guideline for the researchers who want to use piezoelectric materials for engineering structures.

A Review of Piezoelectric Material-Based Structural Control and Health Monitoring Techniques for Engineering Structures: Challenges and Opportunities

This article presents a strategy for enhancing the performance of the synchronized switch damping on inductor technique used for the semiactive control of structural vibrations. This enhancement is achieved by adding a negative capacitance to the resonant circuit that dissipates the energy converted by a piezoelectric transducer embedded in the structure. A unidimensional spring-mass system shunted synchronously to a resonant circuit is studied analytically, and the main parameters governing the performances of the system are highlighted. Experimental results obtained with a synthetic negative capacitance demonstrate the enhancement of the performance of synchronized switch damping on inductor and confirm the parametric dependencies identified analytically.

Synchronized Switch Damping on Inductor and Negative Capacitance

Wave frequency is a critical parameter for applications ranging from structural health monitoring, noise control, and medical imaging to quantum of energy in matter. Frequency conversion is an inevitable wave phenomenon in nonlinear or time-modulated media. However, frequency conversion in linear media holds the promise of breaking limits imposed by the physics laws of wave diffraction such as Snell's law and Rayleigh criterion. In this Letter, we physically introduce a linear active metalayer in a structural beam that can convert the wave frequency of an flexural incidence into arbitrary frequencies of transmitted waves, which is underpinned by time modulation of sensing signals and insensitive to incident amplitude. The active element, involving piezoelectric components and time-modulated transfer function, breaks energy conservation such that the generated harmonics can be fully decoupled, making the frequency conversion linear and independent. By leveraging the time-modulated unit, phase-gradient and frequency-gradient metalayers are proposed for frequency-converted wave steering and dynamic beam steering, respectively. The linear active metalayer proposed herein suggests a promising solution to fully control time-domain signals of flexural waves, in stark contrast with existing elastic metasurfaces, regardless of being passive or active.

Independent Flexural Wave Frequency Conversion by a Linear Active Metalayer.

To unlock the lock of futuristic developments, nowadays shape memory alloys (SMAs) are acting as key by outnumbering the existing smart materials in view of new design competence, innovative techniques, enhanced technologies, and meeting the dire need according to the demand of ongoing scientific and industrial progress. Undoubtedly, it can be worthy to associate SMAs with the term polymorphism, as they possess unique capability to encapsulate multitudinous inherent characteristics under their name. Shape memory effect, superelasticity, and damping are there to name a few among many others, as prime indicators. The exhibition of these characteristics of SMAs is due to the transformation that takes place between austenite phase and martensite phase which is achieved either by temperature or stress variation. The fascinating characteristics they possess enable them to attract researchers and designers toward their potential applications in diverse domain as smart and multi-functional materials. The present work focuses on the review of research works accomplished in the recent 5 years pertaining to modeling and applications of shape memory alloys in distinct domains. Under the topic of modeling, a look into the research carried out on a variety of SMA structures—like functionally graded SMAs, SMA springs, porous SMAs, novel SMA actuators—is presented. In addition to this, the work carried out to represent SMAs with large strains and large rotations and to model polycrystalline SMAs is also covered. This is supplemented by application-oriented domains, each of which disseminates the attributes of SMAs that are self-sufficient to express what factors make SMAs more prominent. It is believed that the foregoing works comprehensively detailed in this review article will certainly lay a solid platform for the future investigations that are going to take place in time to come.

A half a decade timeline of shape memory alloys in modeling and applications

In this work, a surface-bondable multilayer piezoelectric actuator, which utilizes the "33" electromechanical coupling for actuation, has been designed, modeled and tested. This actuator was developed to excite thick and stiff structures. The most commonly used form of piezoelectric actuator -the piezoelectric patches- are typically used for actuating thin beams, plates and shells. But, unlike the piezoelectric patches, which are just bonded to the surface of the substructure with epoxy adhesive, the implementation of the stack actuators present certain drawbacks. Traditionally, the stack actuators have to be either integrated into the structure, or be utilized like an electrodynamic exciter. Both of these methodologies of actuation are accompanied by several complications -large weight penalty being one of them- which render the choice of stack actuators undesirable for several applications. To overcome these shortcomings, and to offer a feasible solution, the concept of the surface-bondable multilayer piezoelectric actuator is proposed in this article. Besides retaining the actuation capabilities of a regular stack actuator, the design of the surface-bondable multilayer piezoelectric actuator allows it to be bonded to the surface of the substructure (like a piezoelectric patch). Thus, this design allows us to access the best of both worlds -the ease of implementation achieved with the patches, and the high actuation capability of the stack actuators. The design of the actuator, the inspiration for the design, the mechanism of operation of the actuator, its performance against other piezoelectric-based actuation methodologies, and the experimental validation of the concept, form the contents of the article.

https://iopscience.iop.org/article/10.1088/1361-665X/ab6698/pdf

P. Shivashankar

Papers

Review on the use of piezoelectric materials for active vibration, noise, and flow control

Independent Flexural Wave Frequency Conversion by a Linear Active Metalayer.

A half a decade timeline of shape memory alloys in modeling and applications

Design, modeling and testing of d 33 -mode surface-bondable multilayer piezoelectric actuator

Nonlinear modeling of d33-mode piezoelectric actuators using experimental vibration analysis