http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Acoustics is the science of sound, including its generation, propagation, and effect. Although the propulsion sources of internal combustion engine (ICE) vehicles and electric motor-powered vehicles (EV) are different and therefore their propulsion noises are different, both types of vehicles have shared noise concerns: Tire and road noise; Wind noise. Vehicle noise and vibration issues have been there almost from the inception of vehicle manufacturing. The noise problem in a vehicle is very severe and is difficult to solve only by modifying the sources of noise and vibration. Sound package treatments address the noise and vibration issues along the path to reduce in-cabin noise. In Acoustical Materials, readers will grasp the science of reducing sound and vibration using sound absorbers, sound barriers, and vibration dampers. Sound provides information on the proper operation of the vehicle, but if unchecked, can detract from the consumer experience within the vehicle and create noise pollution outside the vehicle. Acoustical Materials provides essential information on the basics of sound, vehicle noise source, how these are measured, how vehicle owners perceive sound, and ultimately, how to solve noise problems in vehicles using sound package materials.
Cover -- Table of Contents -- Foreword -- Preface -- Acknowledgments -- About the Author -- List of Acronyms -- CHAPTER 1 Vehicle Acoustics and Understanding of Noise -- 1.1. Typical Frequencies Related to Vehicle Noise -- 1.2. Fundamentals of Acoustics -- 1.2.1 Waves -- 1.2.2 Mathematical Description of Sound Waves -- 1.3. Propagation of Waves -- 1.3.1 Spherical Wave -- 1.3.2 Cylindrical Wave -- 1.3.3 Plane Wave -- 1.4 Sound Power and Sound Intensity -- 1.5 Levels and Decibels -- 1.5.1 Reference Values -- 1.5.2 Adding and Subtracting Decibels -- 1.5.2.1 Adding Decibels -- 1.5.2.2 Subtracting Decibels -- 1.5.3 More on Changes in Decibel Values -- 1.6 Frequency -- 1.6.1 Constant Bandwidth Frequency -- 1.6.2 Constant Percent Bandwidth Frequency -- 1.7 Perception of Sound and Weighting Curves -- 1.8 Performance Descriptors in Sound Package Development Work -- References -- Additional Reading -- CHAPTER 2 Instrumentation and Test Facilities -- 2.1 Performance Characteristics of Instruments -- 2.1.1 Frequency Response -- 2.1.2 Dynamic Range -- 2.1.3 Crest Factor -- 2.1.4 Response Time -- 2.2 Sound Measurements -- 2.2.1 Selection of a Microphone -- 2.2.1.1 Free-Field Microphone -- 2.2.1.2 Random Incidence Microphone -- 2.2.1.3 Pressure Microphone -- 2.2.2 Sound Level Meter -- 2.2.3 Sound Intensity Probe -- 2.2.4 Binaural Measurement System -- 2.2.5 Near-Field Acoustic Holography and Beamforming -- 2.3 Vibration Measurements -- 2.3.1 Accelerometers -- 2.3.2 Impedance Head -- 2.3.3 Laser Vibrometer -- 2.4 Test Facilities -- 2.4.1 Reverberation Room -- 2.4.1.1 Diffusers -- 2.4.2 Anechoic or Hemi-anechoic Room -- 2.4.2.1 Wedge Absorber -- 2.4.2.2 Flat Panel Absorber -- References -- Additional Reading -- CHAPTER 3 Hearing Parameters -- 3.1 Hearing Sound -- 3.2 Equal Loudness Level Contour -- 3.2.1 Loudness Level (Phon) -- 3.2.2 Loudness (Sone).
3.3 Loudness of Complex Sounds -- 3.4 Additional Metrics -- 3.4.1 Sharpness -- 3.4.2 Booming -- 3.4.3 Roughness and Fluctuation Strength -- 3.5 Articulation Index -- References -- CHAPTER 4 Vehicle Noise Sources and Solutions -- 4.1 Vehicle Noise Sources -- 4.1.1 Propulsion System Noises Related to ICE Vehicles -- 4.1.1.1 Engine Noise -- 4.1.1.2 Transmission Noise -- 4.1.1.3 Cooling System -- 4.1.1.4 Intake Noise -- 4.1.1.5 Exhaust Noise -- 4.1.2 Propulsion System Noises Related to EVs -- 4.1.2.1 Motor Noise -- 4.1.2.2 Gear Reduction System Noise -- 4.1.2.3 Inverter Noise -- 4.1.3 Brake Noise -- 4.1.4 Road Noise -- 4.1.5 Tire Noise -- 4.1.6 Wind Noise -- 4.1.6.1 Wind Flutter -- 4.1.6.2 Windrush -- 4.1.7 Relative Spectral Distribution between ICE and EV -- 4.2 Some Specialty Noises -- 4.2.1 Climate Control (HVAC) Noise -- 4.2.2 Power Accessory Noise -- 4.3 The Noise System -- 4.3.1 Source-Path-Receiver System -- 4.4 Noise Control Design Approach: Source, Path, and Receiver -- 4.4.1 Noise Control at the Source -- 4.4.2 Noise Control along the Path -- 4.4.2.1 Materials for Airborne Noise Control -- 4.4.2.2 Materials for Structure-Borne Noise Control -- 4.4.3 Noise Control at the Receiver -- References -- Additional Reading -- CHAPTER 5 Sound Absorber -- 5.1 Sound Absorption Materials and Their Applications -- 5.1.1 Typical Materials -- 5.1.2 Typical Absorber Applications -- 5.2 Acoustical Descriptor of an Absorber -- 5.2.1 Sound Absorption Coefficients -- 5.2.1.1 Normal Incidence Sound Absorption Coefficient -- 5.2.1.2 Random Incidence Sound Absorption Coefficient -- 5.2.1.3 Statistical (Energy) Sound Absorption Coefficient -- 5.3 How Does It Work -- 5.3.1 Various Factors Effecting Sound Absorption -- 5.4 Particle Velocity and Thickness -- 5.4.1 Thickness, Density, and Air Gap -- 5.5 How Sound Is Absorbed -- 5.5.1 Porosity -- 5.5.2 Airflow Resistivity.
5.5.3 Tortuosity -- 5.5.4 Viscous Length -- 5.5.5 Thermal Length -- 5.5.6 Predicting Sound Absorption Performance -- 5.6 Absorber Surface Treatment -- 5.6.1 Film -- 5.6.2 Film with an Opening: Helmholtz Resonator -- 5.6.3 Perforated Film with Absorber Backing -- 5.6.4 Scrim -- References -- Additional Reading -- CHAPTER 6 Sound Barrier -- 6.1 Barrier Materials and Their Applications -- 6.1.1 Typical Materials -- 6.1.2 Typical Barrier Applications -- 6.2 Acoustical Descriptor of a Barrier -- 6.3 How Does It Work -- 6.3.1 Nonporous -- 6.3.2 Limp -- 6.3.3 Massive -- 6.4 Sound Transmission Loss Performance -- 6.4.1 Region I: Stiffness and Resonance-Controlled Region -- 6.4.2 Region II: Mass-Controlled Region -- 6.4.3 Region III: Coincidence and Stiffness-Controlled Region -- 6.5 Mass Law Performance of a Panel -- 6.5.1 Normal Incidence -- 6.5.2 Grazing Incidence -- 6.5.3 Random Incidence -- 6.5.4 Field Incidence -- 6.6 Sound Transmission Loss of Single Wall Constructions -- 6.7 Sound Transmission Loss of Double Wall Constructions -- 6.7.1 Coupled Mass Region -- 6.7.2 Double Wall Resonance Point -- 6.7.3 Transition Region -- 6.7.4 Intercept Point -- 6.7.5 Double-Wall Decoupled Region -- 6.8 Effect of Holes in a Barrier -- 6.9 Dissipative System -- References -- Additional Reading -- CHAPTER 7 Vibration Damper -- 7.1 Damping Materials and Their Applications -- 7.1.1 Typical Materials -- 7.1.2 Typical Damper Applications -- 7.2 Acoustical Descriptor of a Damper -- 7.3 How Does It Work -- 7.3.1 Polymers -- 7.3.2 Viscoelasticity -- 7.3.3 Behavior of Viscoelastic Materials -- 7.3.4 How to Determine the Glass Transition Temperature -- 7.4 Damping Treatments -- References -- Additional Reading -- CHAPTER 8 Case Studies -- 8.1 Engine Compartment Sound Package Treatments -- 8.2 Vehicle Interior Sound Absorption Treatments -- 8.2.1 Floor Carpet Pile.
8.2.2 Headliner -- 8.2.3 Seats -- 8.3 Vehicle Interior Sound Insulation Treatments -- 8.3.1 Dashmat -- 8.3.1.1 Barrier Decoupler Dashmat -- 8.3.1.2 Dissipative Dashmat -- 8.3.2 Floor Carpet -- 8.3.2.1 Barrier Decoupler Floor Carpet -- 8.3.2.2 Dissipative Floor Carpet -- 8.3.3 Door System -- 8.3.4 Backlight Trim Panel -- 8.4 Vehicle Interior Vibration Treatments -- 8.4.1 Laminated Panels -- 8.4.2 Laminated Glass -- 8.5 Passthroughs -- 8.6 Noise Control Patches -- 8.7 Body Cavity Fillers -- References -- CHAPTER 9 Test Methods -- 9.1 Standards and Specifications -- 9.1.1 Standards -- 9.1.2 Specifications -- 9.2 Different Test Methods -- 9.3 Airflow Resistance Tests -- 9.4 Sound Absorption Tests -- 9.4.1 Normal Incidence Sound Absorption Test -- 9.4.1.1 Roving Microphone and Standing Wave Ratio Method -- 9.4.1.2 Two-Microphone Method -- 9.4.1.3 Results of Normal Incidence Sound Absorption Tests -- 9.4.2 Random Incidence Sound Absorption Test -- 9.4.3 Differences between Normal and Random Incidence Sound Absorption Tests -- 9.5 Sound Transmission Loss Tests -- 9.5.1 Normal Incidence STL Test -- 9.5.2 Field Incidence STL Test -- 9.5.2.1 Correlation Factor Based Measurement -- 9.5.2.2 Two Reverberation Room Based Measurement -- 9.5.2.3 Sound Intensity Based Measurement -- 9.5.3 IL Tests for Body Cavity Filler Materials -- 9.6 Vibration Damping Tests -- 9.6.1 Complex Modulus Test (Oberst Bar Test) -- 9.6.1.1 System Performance Based Measurement -- 9.6.1.2 Material Property Evaluation Based Measurement -- 9.6.2 Mechanical Impedance Test (CenterPoint Test) -- 9.7 A Few Other Material Testing Methods -- 9.7.1 Apamat and Acoustic Gravelometer -- 9.7.2 Panel Damping Measurement -- 9.8 Component Level Tests -- 9.8.1 Airborne Noise Test -- 9.8.2 Structure-Borne Noise Test -- 9.9 Vehicle Level Tests -- 9.9.1 Engine Noise Test -- 9.9.2 Road Noise Test.
9.9.3 Wind Noise Test -- References -- Additional Reading -- CHAPTER 10 Closing the Loop -- 10.1 Speed of Sound with Temperature, Humidity, and Barometric Pressure -- 10.2 Addition and Subtraction of Decibels -- 10.2.1 Mathematical Approach -- 10.2.2 Nomogram Approach -- 10.2.3 Shortcut Approach -- 10.3 Test Facilities -- 10.3.1 Facility Site Selection -- 10.3.2 Design Goals for Testing Needs and Requirements -- 10.3.3 Laboratory Layout and Dimensions -- 10.3.4 HVAC and Mechanical Equipment System Design -- 10.4 Designing a Reverberation Room -- 10.4.1 Cutoff Frequency -- 10.4.2 Schroeder Frequency -- 10.4.3 Room Dimensions -- 10.4.4 Normal Modes -- 10.5 Size of Anechoic and Hemi-anechoic Rooms -- 10.6 Reduced Frequency Nomogram -- 10.7 Some Thoughts on Statistical Energy Analysis -- 10.8 How to Develop Acoustic Targets for Sound Package Treatments -- 10.9 Testing of Passthroughs -- References -- Additional Reading -- Index.
TECHNOLOGY & ENGINEERING / Acoustics & Sound