Cover Image

Acoustical materials : solving the challenge of vehicle noise /

Bibliographic Details
Main Author: Saha, Pranab, 1951- (Author)
Corporate Author: Knovel (Firm)
Format: eBook
Language:English
Published: Warrendale, Pa. (400 Commonwealth Dr., Warrendale PA USA) : Society of Automotive Engineers, 2020.
Edition:1st ed.
Series:Society of Automotive Engineers. Electronic publications
Subjects:
Automobiles > Noise.
Noise control.
Acoustical engineering.
Automobiles > Bruit.
Bruit > Lutte contre.
Acoustique appliquée.
noise control.
TECHNOLOGY & ENGINEERING / Automotive.
TECHNOLOGY & ENGINEERING / Acoustics & Sound.
Acoustical engineering
Automobiles > Noise
Noise control
Automotive technology and trades.
Acoustic and sound engineering.
Electronic books.
Online Access:Connect to the full text of this electronic book
Table of Contents:
  • 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.