机械振动噪声与控制 参赛课件

Chapter 1 Introduction
1. 1 Mechanical Vibration and Control
1.1.1 Summary of Mechanical Vibration Undesirable vibrations： Vehicle; Noise; Machines & Structures; Earthquake;
1. 1 Mechanical Vibration and Control
1.1.3 Model of Vibration System
离散系统 （集中参数系统）
Discrete system (Lumped parameter system)
连续系统 （分布参数系统）
Continuous system (Distributed parameter system)
Free vibration — the periodic motion occurring when an elastic
Vibrations with Applications (5th ed.), Prentice Hall, 1997
2. • R.F. Barron, Industrial Noise Control and Acoustics, Marcel Dekker, 2003 3. •郑兆昌主编， 机械振动（上册），机械工业出版社，
1980
4. •商大中，动力分析基础，哈尔滨工程大学出版社，1999 5. •季文美，机械振动，科学出版社， 1985
Chapter 1 Introduction
1. 1 Mechanical Vibration and Control
1.1.1 Summary of Mechanical Vibration Vibrating Phenomena in the World Vibration are found in many branches of science and engineering
Fundamentals of Mechanical Vibration and Noise
参赛选手：****
教科书（Textbook）: 赵玫等，机械振动与噪声学， 科学出版社， 2004
参考书（Reference Books）:
1. W.T. Thomson and M.D. Dahleh, Theory of
Research aim ?
1. Elimination or suppression of undesirable vibrations 2. Generation of the necessary forms and quantities of useful vibrations
Chapter 1 Introduction
Power units in every kinds of vessels may cause vibrations
Chapter 1 Introduction
1. 1 Mechanical Vibration and Control
1.1.1
Summary of Mechanical Vibration
z
θ θ
多自由度系统振动 (multiple degree of freedom)
A
B
A
B
Chapter 1 Introduction
模型与自由度 (Model and degree of freedom)
Chapter 1 Introduction
1. 1 Mechanical Vibration and Control
Chapter 1 Introduction
1. 1 Mechanical Vibration and Control
1.1.4 Clarification of Mechanical Vibrations
(1) 按自由度分(According to the degree of freedom) The least number of mutually independent parameters (coordinates) required to uniquely define a material system's position in space, time,ing vibration; harmonic oscillator, resonator; Vibrating road roller; Vibrating feeder; Vibrating forming machine.
Chapter 1 Introduction
1.1.4 Clarification of Mechanical Vibrations
(2) 按激励形式分(According to the excitation) ：
自由振动 (free vibration) (no force) 强迫振动 (forced vibration) (external force)
1. 1 Mechanical Vibration and Control
1.1.2 Basic Concept Mechanical Vibration ?
Vibration is a phenomena that a body or structure oscillates about some specified reference point. Vibration is commonly expressed in terms of frequency , amplitude and Phase angle.
单自由度系统振动 (single degree of freedom)
多自由度系统振动 (multiple degree of freedom) 连续系统振动 (continuous system)
Chapter 1 Introduction
单自由度系统振动 (single degree of freedom)