AM4008 Noise, Vibration and Harshness for Automobiles Syllabus:
AM4008 Noise, Vibration and Harshness for Automobiles Syllabus – Anna University PG Syllabus Regulation 2021
OBJECTIVES:
The course should enable the students to:
1. To introduce source of noise and vibration
2. To broaden the understanding of sound measurement and human sensitivity
3. To underline the importance of simulation, anechoic chamber and acoustic holography
4. To broaden the importance of statistical and frequency analysis
5. To introduce active control techniques
UNIT I NVH IN THE AUTOMOTIVE INDUSTRY
Sources of noise and vibration. Design features. Common problems. Marque values. Noise quality. Pass-by noise requirements. Target vehicles and objective targets. Development stages in a new vehicle programme and the altering role of NVH engineers.
UNIT II SOUND AND VIBRATION THEORY
Sound measurement. Human sensitivity and weighting factors. Combining sound sources. Acoustical resonances. Properties of acoustic materials. Transient and steady state response of one degree of freedom system applied to vehicle systems. Transmissibility. Modes of vibration.
UNIT III TEST FACILITIES AND INSTRUMENTATION
Laboratory simulation: rolling roads (dynamometers), road simulators, semi-anechoic rooms, wind tunnels, etc. Transducers, signal conditioning and recording systems. Binaural head recordings. Sound Intensity technique, Acoustic Holography, Statistical Energy Analysis
UNIT IV SIGNAL PROCESSING
Sampling, aliasing and resolution. Statistical analysis. Frequency analysis. Campbell’s plots, cascade diagrams, coherence and correlation functions.
UNIT V NVH CONTROL STRATEGIES & COMFORT
Source ranking. Noise path analysis. Modal analysis. Design of Experiments, Optimisation of dynamic characteristics. Vibration absorbers and Helmholtz resonators. Active control techniques.
TOTAL: 45 PERIODS
OUTCOMES:
Upon completion of this course the student will be able to:
1. Identify sources of noise and vibration
2. Measure sound intensity and human sensitivity
3. Carryout statistical energy analysis and simulators
4. Determine active control techniques
5. Carryout statistical and frequency analysis barrier.
REFERENCES:
1. Allan G. Piersol ,Thomas L. Paez “Harris’ shock and vibration hand book” , McGraw-Hill ,New Delhi, 2010
2. Clarence W. de Silva , “Vibration Monitoring, Testing, and Instrumentation “,CRC Press,2007
3. Colin H Hansen “Understanding Active Noise Cancellation “ , Spon Press , London .2003
4. David A.Bies and Colin H.Hansen “Engineering Noise Control: Theory and Practice “ Spon Press , London . 2009
5. Matthew Harrison “Vehicle Refinement: Controlling Noise and Vibration in Road Vehicles “,Elsevier Butterworth-2004