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2019 | Buch

Piezoelectric Sensors and Actuators

Fundamentals and Applications

verfasst von: Dr. Stefan Johann Rupitsch

Verlag: Springer Berlin Heidelberg

Buchreihe : Topics in Mining, Metallurgy and Materials Engineering

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SUCHEN

Über dieses Buch

This book introduces physical effects and fundamentals of piezoelectric sensors and actuators. It gives a comprehensive overview of piezoelectric materials such as quartz crystals and polycrystalline ceramic materials. Different modeling approaches and methods to precisely predict the behavior of piezoelectric devices are described. Furthermore, a simulation-based approach is detailed which enables the reliable characterization of sensor and actuator materials.

One focus of the book lies on piezoelectric ultrasonic transducers. An optical approach is presented that allows the quantitative determination of the resulting sound fields. The book also deals with various applications of piezoelectric sensors and actuators. In particular, the studied application areas are

· process measurement technology,

· ultrasonic imaging,

· piezoelectric positioning systems and

· piezoelectric motors.

The book addresses students, academic as well as industrial reseachers and development engineers who are concerned with piezoelectric sensors and actuators.

Inhaltsverzeichnis

Frontmatter
Chapter 1. Introduction
Abstract
Piezoelectric devices play a major role in our everyday lives. Currently, the global demand for piezoelectric devices is valued at approximately 20 billion euros per year. Piezoelectric sensors and actuators make a substantial contribution in this respect. At the beginning of the opening chapter, we will discuss the fundamentals of sensors and actuators. Section 1.2 addresses the history of piezoelectricity and piezoelectric materials. In Sect. 1.3, application areas as well as application examples of piezoelectricity are listed. The chapter ends with a brief chapter overview of the book.
Stefan Johann Rupitsch
Chapter 2. Physical Basics
Abstract
Piezoelectric sensors and actuators connect different physical fields (e.g., electrostatic and mechanical field). With a view to studying the behavior of piezoelectric devices, the fundamentals of those physical fields are indispensable. Therefore, this chapter addresses the physical principles that are important for piezoelectric sensors and actuators. Section 2.1 deals with electromagnetics, especially with the electric field. In Sects. 2.2 and 2.3, the basics of continuum mechanics and acoustics are described, respectively.
Stefan Johann Rupitsch
Chapter 3. Piezoelectricity
Abstract
In this chapter, we will discuss the physical effect of piezoelectricity, which describes the interconnection of mechanical and electrical quantities within materials. Sect. 3.1 details the principle of the piezoelectric effect. Thereby, a clear distinction is made between the direct and the inverse piezoelectric effect. Since different coupling mechanisms take place within piezoelectric materials, we will conduct in Sect. 3.2 thermodynamical considerations allowing a distinct separation of the coupling mechanisms. Subsequently, the material law for linear piezoelectricity will be derived that is given by the constitutive equations for piezoelectricity. By means of these equations, one is able to connect mechanical and electrical quantities. In Sect. 3.4, the electromechanical coupling within piezoelectric materials is classified. This includes intrinsic and extrinsic effects as well as different modes of piezoelectricity. Afterward, we introduce electromechanical coupling factors, which rate the efficiency of energy conversion within piezoelectric materials, i.e., from mechanical to electrical energy and vice versa. Section 3.6 finally concentrates on the internal structure of various piezoelectric materials (e.g., piezoceramic materials), the underlying manufacturing process as well as typical material parameters.
Stefan Johann Rupitsch
Chapter 4. Simulation of Piezoelectric Sensor and Actuator Devices
Abstract
In this chapter, we will study the fundamentals of the FE method, which are important for simulating the behavior of piezoelectric sensors and actuators. The focus lies on linear FE simulations. Section 4.1 deals with the basic steps of the FE method, e.g., Galerkin?s method. Subsequently, the FE method will be applied to electrostatics (see Sect. 4.2), the mechanical field (see Sect. 4.3), and the acoustic field (see Sect. 4.4). At the end, we will discuss the coupling of different physical fields because this represents a decisive step for reliable FE simulations of piezoelectric sensors and actuators. For a better understanding, the chapter also contains several simulation examples.
Stefan Johann Rupitsch
Chapter 5. Characterization of Sensor and Actuator Materials
Abstract
The chapter starts with standard approaches for characterizing active and passive materials. The fundamentals of the inverse method regarding material characterization are detailed in Sect. 5.2. In Sects. 5.3 and 5.4, the inverse method will be used to identify the complete data set of piezoceramic materials and the dynamic mechanical behavior of homogenous passive materials such as thermoplastics.
Stefan Johann Rupitsch
Chapter 6. Phenomenological Modeling for Large-Signal Behavior of Ferroelectric Materials
Abstract
This chapter primarily deals with Preisach hysteresis modeling, which represents a phenomenological modeling approach for the large-signal behavior of ferroelectric materials. Before we study in Sect. 6.3 alternative phenomenological modeling approaches that also focus on the macroscopic transfer behavior of ferroelectric materials, hysteresis will be mathematically defined. Moreover, an overview of material models on different length scales (e.g., atomistic scale) is given in Sect. 6.2. Contrary to phenomenological modeling approaches, those material models aim at describing the physical behavior of ferroelectric as accurate as possible. In Sect. 6.4, we will introduce the classical Preisach hysteresis operator \(\mathcal {H}_\text {P}\), which comprises weighted elementary switching operators. Section 6.5 details different weighting procedures for the elementary switching operators. Because the classical Preisach hysteresis operator is only suitable to a limited extent for predicting hysteretic behavior of ferroelectric actuators in practical applications, a so-called generalized Preisach hysteresis model (operator \(\mathcal {H}_\text {G}\)) will be introduced in Sect. 6.6. This extended Preisach hysteresis model enables, e.g., the consideration of asymmetric behavior in hysteresis curves. After that, a parameter identification strategy is presented which allows reliable predictions of electrical and mechanical quantities through Preisach hysteresis modeling. To apply Preisach hysteresis modeling in practical applications of ferroelectric actuators (e.g., in high precision positioning systems), it is of utmost importance to invert the Preisach hysteresis operator. Owing to this fact, Sect. 6.8 finally addresses an iterative inversion procedure, which enables efficient determinations of the aimed electrical excitation signals in a reasonable time.
Stefan Johann Rupitsch
Chapter 7. Piezoelectric Ultrasonic Transducers
Abstract
This chapter addresses piezoelectric ultrasonic transducers that are specially designed to generate and receive sound waves in fluid media, i.e., air or water. Moreover, we will also discuss ultrasonic transducers for medical diagnostics. Section 7.1 deals with a semi-analytical approach to calculate sound fields and electrical transducer outputs for common transducer shapes, e.g., piston-type transducers. In doing so, the complex structure of a piezoelectric ultrasonic transducer is reduced to an active surface, which can generate and receive sound pressure waves. The semianalytical approach will be used in Sect. 7.2 to determine sound fields as well as directional characteristics of common transducers. Section 7.3 details the axial and lateral spatial resolution of spherically focused transducers operating in pulse-echo mode. In Sect. 7.4, we will study the general structure of piezoelectric ultrasonic transducers. This includes single-element transducers, transducer arrays as well as piezoelectric composite transducers. Afterward, a simple one-dimensional modeling approach is shown that allows analytical description of basic physical relationships for piezoelectric transducers under consideration of their internal structure. Section 7.6 contains selected examples for piezoelectric ultrasonic transducers. Finally, a brief introduction to the fundamental imaging modes of ultrasonic imaging will be given which is an important application of piezoelectric ultrasonic transducers.
Stefan Johann Rupitsch
Chapter 8. Characterization of Sound Fields Generated by Ultrasonic Transducers
Abstract
The metrological characterization of sound fields represents an important step in the design and optimization of ultrasonic transducers. In this chapter, we will concentrate on the so-called light refractive tomography (LRT), which is an optical-based measurement principle. It allows noninvasive, spatially as well as temporally resolved acquisition of both, sound fields in fluids and mechanical waves in optical transparent solids. Before the history and fundamentals (e.g., tomographic reconstruction) of LRT are studied in Sects. 8.2 and 8.3, we will discuss conventional measurement principles (e.g., hydrophones) for such measuring tasks. Section 8.4 addresses the application of LRT for investigating sound fields in water. For instance, the disturbed sound field due to a capsule hydrophone will be quantified. In Sect. 8.5, LRT results for airborne ultrasound are shown and verified through microphone measurements. Finally, LRT will be exploited to quantitatively acquire the propagation of mechanical waves in optically transparent solids, which is currently impossible by means of conventional measurement principles.
Stefan Johann Rupitsch
Chapter 9. Measurement of Physical Quantities and Process Measurement Technology
Abstract
In this chapter, we will concentrate on a few selected physical quantities that are important in process measurement technology. Section 9.1 deals with the typical designs of piezoelectric sensors for the mechanical quantities force, torque, pressure, and acceleration. Subsequently, an ultrasound-based method will be described which enables the simultaneous determination of plate thickness and speed of sound inside the plate. Section 9.3 treats the metrological registration of fluid flow by means of ultrasonic waves. At the end of the chapter, a piezoelectric device will be presented that can be used as cavitation sensor in ultrasonic cleaning.
Stefan Johann Rupitsch
Chapter 10. Piezoelectric Positioning Systems and Motors
Abstract
The chapter starts with the fundamentals of piezoelectric stack actuators as well as the effect of mechanical prestress on the stack performance. Preisach hysteresis modeling from Chap. 6 will be applied to describe the large-signal behavior of prestressed stack actuators. Section 10.2 deals with so-called amplified piezoelectric actuators, which provide relatively large mechanical displacements by converting mechanical forces into displacements. The conversion is performed with the aid of special metallic hinged frames. In Sect. 10.3, the applicability of piezoelectric trimorph actuators for positioning tasks will be demonstrated. For this purpose, model-based hysteresis compensation is conducted. At the end of the chapter, a brief overview of piezoelectric motors will be given which includes selected examples of linear as well as rotary motors.
Stefan Johann Rupitsch
Backmatter
Metadaten
Titel
Piezoelectric Sensors and Actuators
verfasst von
Dr. Stefan Johann Rupitsch
Copyright-Jahr
2019
Verlag
Springer Berlin Heidelberg
Electronic ISBN
978-3-662-57534-5
Print ISBN
978-3-662-57532-1
DOI
https://doi.org/10.1007/978-3-662-57534-5