Preface

Noise and vibration are two interrelated terms in the field of engineering. Vibration is caused by unbalanced inertial forces and moments, whereas noise is the result of such vibrations. Such phenomena have always been a matter of concern for both researchers and practicing engineers. The lower level of vibration can ensure less tear and wear, less tolerance, and longer fatigue life of the machine or structure. This book presents the established fundamentals in the area of passive, semi-active, and active vibration control, and explores the new and emerging technologies and techniques. There has been a considerable amount of effort devoted to the development and realization of methodologies for the control of sound and vibration, and this book covers the latest theoretical, algorithmic, and practical applications, including:

*Chapter 1:* A hysteresis nonlinear model is established for a giant magnetostrictive actuator to fully describe the actuator dynamic characteristics.

*Chapter 2:* The dynamic modeling and simulation of proportional–integral– derivative controls for rail car systems are investigated.

*Chapter 3:* Effective low-frequency noise insulation active damping approaches are illustrated to improve a structure's noise insulation performance.

*Chapter 4:* The dynamic behavior of aero-elastic vibrations in the presence of nonlinear stiffness such as free-play mechanisms and softening or hardening stiffness is investigated.

*Chapter 5:* Background information on the assistance of ultrasonic vibration in the hot glass embossing process is provided.

*Chapter 6:* The generation mechanism of the self-sustained tone is clarified experimentally and numerically, and the methods for suppressing a self-sustained tone using baffle plates and perforated plates are investigated.

*Chapter 7:* The relationship between energy of vibration and noise signals measured in the magnetic resonance imaging scanning area and its vicinity are mapped to minimize these negative impacts.

*Chapter 8:* Empirical results quantifying various signals from heartbeat to material vibration are investigated.

It is my hope that this book, which integrates the modeling and design aspects of various noise and vibration control techniques, will serve as a comprehensive guide and reference for practicing engineers and educators, and, more importantly, is a welcome-mat for recent graduates entering the vibration control engineering profession.

> **Dr. Ehsan Noroozinejad Farsangi** Assistant Professor, Department of Earthquake Engineering, Graduate University of Advanced Technology, Kerman, Iran

Chapter 1

Abstract

control, active control

1. Introduction

agency [5, 6].

1

Active Control

Nonlinear Giant Magnetostrictive

Actuator and Its Application in

Lihua Yang, Haipeng Zhang, Hailong Jiang, Shuyong Liu,

Haiping Wu, Haifeng Li and Ehsan Noroozinejad Farsangi

The giant magnetostrictive actuator has great use in vibration control, but the linear model cannot fully describe its dynamic characteristics. In this chapter, based on the domain wall theory and piezomagnetic theory, a hysteresis nonlinear model is established to fully describe the actuator dynamic characteristics. In combination with the regularisation method, a sliding mode controller has been designed, and the giant magnetostrictive actuator is also studied in the application of active control. Experimental results show that the hysteresis nonlinear model proposed in the chapter can fully describe the actuator's dynamic characteristics in a wider frequency band and the active control also has a much better isolation effect than the passive vibration; it can significantly attenuate the external incentives.

Keywords: giant magnetostrictive actuator, hysteresis nonlinearity, sliding mode

Passive vibration isolation has been widely used as an effective isolation method; it can significantly reduce the vibration transmission between mechanical equipment and the base, while the isolation effect is limited in the micro-vibration and low frequencies. Therefore, the active control has been a focus of research at home and abroad [1–4]. With the development of smart materials, intelligent actuators manufactured by those materials including the magneto-rheological actuator, shape memory alloy actuator, giant magnetostrictive actuator (GMA), and others. These actuators have played a huge role in promoting the active control as the executing

With the advantages of high-positioning accuracy, fast response, and wide frequency band, among others, the GMA has a wide variety of applications in fields including vibration control and precision positioning [7–10]. Many scholars have studied the linear modelling method of GMA, which is only suitable for describing low-frequency dynamic characteristics [11, 12]. However, the hysteresis nonlinear model based on the domain walls theory can more clearly reveal the coupling relationship among the magnetization process, the stress magnetic machine effect, and stretching amount, and it can more fully describe the GMA's dynamic characteristics on a wide frequency band [13], which is suitable for the active control
