NVH at MTU NVH at MTU Presented by

Mohan D. Rao Associate Professor

Mechanical Engineering -Engineering Mechanics Department

ME-EM NVH FacultyME-EM NVH Faculty

Jason Blough (jrblough@mtu.edu) - Rotating Equipment, Digital

Signal Processing (DSP), Sound Quality

Harold Evensen (haevense@mtu.edu) - Noise Control, DSP

Gordon Parker (ggparker@mtu.edu)- Control Systems

Chris Passerello (cepass@mtu.edu) - System Dynamics, FEM

Mohan Rao (mrao@mtu.edu)– Acoustics, Noise Control, Sound Quality, Material Damping, VibrationsChuck Van Karsen (cdvankar@mtu.edu) – Modal Analysis, Vibro-acoustics, DSP

NVH Related CoursesNVH Related Courses

MEEM 4160 Experimental Stress Analysis I MEEM 4403 Computer-Aided Design MEEM 4404 Mechanism Synthesis/Modeling MEEM 4701 Analytical/Experimental Modal Analysis MEEM 4704 Acoustics and Noise Control MEEM 5160 Experimental Stress Analysis II MEEM 5700 Dynamic Signal Analysis MEEM 5702 Analytical Vibro-Acoustics MEEM 5703 Experimental Vibro-Acoustics MEEM 6701 Advanced Acoustics Ford/MTU Powertrain NVH Level II

FacilitiesFacilitiesModal Analysis Lab

FacilitiesFacilities

Reverberant Chamber Anechoic Chamber

FacilitiesFacilities

Classroom and Project Area Sound Quality Lab

FacilitiesFacilities

MEEM/KRC Hydraulic Actuator

EquipmentEquipmentHardware:Laboratory Data Acquisition:

HP VXI 80 channelsLMS Scadas III (16 ch.); Siglab 16 ch.

Portable Data Acquisition:TEAC DAT 16 channelsSony DAT 8 channelsRoad Runner 88 channelSymphonie System (01dB, Inc.) 2 ch.DSS system from L&D (112 channels)

Aachen Head for Sound QualityTransducers

Force, acceleration, dynamic strain (over 100)Laser VibrometerMicrophone array - 64 channelsGRAS Sound Intensity Probes

Sound level meters & microphonesImpedance tube (for acoustic absorption & TL measurements)

Lms Cada-XLms Test.LabLms Virtual.LabME'ScopeSmart OfficeO1 dB, dBfa software

Matlab, Labview

Catia, Ideas, Abacus MSC Nastran

MTS Sound Quality & Jury Testing Software

Software:

Capabilities & StrengthsCapabilities & Strengths

Sound Quality – Jury testing and metric developmentModal Analysis – Measurement techniques for difficult structuresOrder Tracking – Develop new algorithms and filtering techniquesTransfer Path Analysis – Both stiffness and indirect matrix methodsOperating Shape Measurement – Using accelerometers and microphones – in transfer cases, transmissions & cabsPassive and Active Noise and Vibration Control – Structural vibration control to reduce interior noise levels, Damping applicationsEngine & Powertrain Mount Characterization – Linear and non-linear characterization methods, effects of aging Full system noise and vibration reduction – Snowmobiles, Compactors, Loaders, Passenger vehicles & AppliancesUnique measurement problems – locomotive bearing stress, telescope vibration, mine blast shock testing, 6 DOF force measurements, pressure ripple in hydraulic lines Specialized DSP development – order tracking, filtering, SQ, …etc.

Sample ProjectsSample Projects

Various projects on sound quality of power seat adjusters, power windows, power mirrors, vacuum cleaners and other appliances.Application of passive damping of engine and gear covers usingviscoelastic materials.Diagnostic and reduction of noise and vibration radiation from a steering column and a prop shaftAssessment and ranking of various sources of engine noise using sound intensity and near field acoustic holography.Dynamic characterization of engine mounts including study on the effects of aging due to fatigue and high mileage.Dynamic modeling including damping of mounts and shock

absorbers using linear and non-linear models using road data.Development of an integrated muffler/trap system for a diesel engine.

SponsorsSponsors

Ford Motor Corp. VisteonGeneral Motors AutoLivDaimler-Chrysler CaterpillarLMS (training courses) John DeereTACOM WhirlpoolTrane PolarisArctic Cat MDOTVibracoustic Corporation US NavyInternational Snowmobile Manufacturer’s AssociationCanadian Department of National DefenseBorg Warner Torque TransferGeneral Electric TransportationVolvo Construction EquipmentTRW, Johnson Controls, NIOSH

MDOT Sound Quality ProjectMDOT Sound Quality Project

MDOT Jury study on passby noise of tire/road surface interaction

Determine noise generated at tire/road surface interface and correlate these with what people consider as annoying or objectionable from the roadside.Acquired passby noise on approximately 20 different surfacesPerformed Jury test to determine preferences

Time domain mount characterization(Ford)

Time domain mount characterization(Ford)

Objective: Develop better ways to characterize powertrain and suspension mounts.

Powertrain mount aging study(Ford, GM & DC)

Powertrain mount aging study(Ford, GM & DC)

Objective: Understand how mount properties change as they age.

1000

1500

2000

2500

3000

3500

0 50 100 150 200 250Axial Frequency (Hz)

K* (N

/mm

)

Axial K* (N/mm) 1500 N/mm New MountsAxial K* (N/mm) 1500 N/mm Fleet Vehicle Mounts (30-40 K miles)Axial K* (N/mm) 1500 N/mm Durability Vehicle Mounts (30-40 K mile)

1500 N/mm Mounts – New, Fleet and Durability Vehicles

Damping of Gear Covers(Cummins Engine)

Damping of Gear Covers(Cummins Engine)

Diesel Engine Gear Cover… Double-Sided

Damping of Side Window Glass (GM)Damping of Side Window Glass (GM)

SHAKER LASER

FORCE TRANDSUCER

VEHICLE SIDE GLASSW/ 4cm GRID SPACING

Steering Column Vibration (Ford)Steering Column Vibration (Ford)

Energy Flow Using SEA Energy Flow Using SEA

Wheel Well Fire Wall

Foot WellTunnel

Floor Pan

Vehicle front of dash showing major parts of the SEA model.

Extended FOD model including the engine compartment and the acoustic cavities.

The power input into the driver’s side, acoustic cavity from the various connected subsystems.

Active Structural Acoustic Control (ASAC)(GM)

Active Structural Acoustic Control (ASAC)(GM)

Objective: To reduce road noise in the 80-300Hz region using a method to cancel forces at suspension attachments.

Data Acquisition System DevelopmentData Acquisition System Development

Working with individual data acquisition system manufacturers to assemble a more capable vehicle data acquisition system

Capabilities include time synchronized data fromVehicle bus (nearly all buses supported)Typical NVH type data w/24 bit ADCs, 80+channelsVideo from USB/Firewire based camerasPosition information from high-precision survey grade GPS w/20+ Hz update rate, when appropriate multiple GPS units can be used to get vehicle orientation as well as position. (~1 cm accuracy)Other channels from remote transducers

Working to wirelessly synchronize multiple systems to allow for example one system on side of test track and one in vehicle.

Snowmobile Passby Noise Snowmobile Passby Noise

Snowmobile noise standard developmentReplace J192 w/ sound power type testFunded by ISMA to improve testing process

Reduce the variability due to changing environmental conditionsUse calibrated sound power source to characterize environment and develop an environmental calibration factor

Measure the sound power and 50ft microphone levels under 46 conditions using calibrated sound power source.Sound Power Sound pressure levelTemperature Depth of fresh snowHumidity Snow densityBarometric Pressure

Vibration of Automotive Transfer CaseVibration of Automotive Transfer Case

(Borg Warner)

Measurement of transverse chain vibration in an automotive transfer case under operating conditions.

Educational Programs in NVHEducational Programs in NVH

Continuing Education Courses in NVH The NVH group at MTU offers a variety of short courses to

industries. These courses originally developed in 1989 to Ford engineers.The duration of these intensive short courses vary from 3 days to 10

days depending on topics selected. The usual format of the course is lectures in the mornings followed

by hands-on laboratory sessions in the afternoons. Topics- Modal analysis, operating shapes, digital signal processing,

FFT analyzers, order tracking, noise control, sound power, soundintensity, sound quality, damping, SEA, NPA.

NVH Enterprise (new)Provides undergraduate students hands-on experience solving real-world NVH problems by applying both technical and business skills. Team learning & undergraduate research. Steady supply of qualified & trained students to meet industry needs

Ford-MTU Distance Education M.S. and Ph.D. ProgramsPlease visit ME-EM web site www.me.mtu.edu for more information

Recent PublicationsRecent PublicationsRao, M.D., and Black, M.D., “Evaluation and Reduction of Steering Column Vibration of a Real Wheel Sedan,” International Journal of Vehicle Noise and Vibration, 1, 122-141. 2004. Rao, M.D., Wirkner, K.J., and Gruenberg, S., “Dynamic Characterization of Automotive Exhaust Isolators”, Journal of Automobile Engineering, Vol. 218, 891-900, 2004.Rao, M.D., “ Recent Applications of Viscoelastic Damping for Noise and Vibration Control in Automobiles and Commercial Airplanes, Journal of Sound and Vibration, 262, 457-474, 2003.Holt, J., Rao, M.D., Blough, J., and Gruenberg, S., “ The Use of Unique Time History Input Excitation in the Dynamic Characterization of Automotive Mounts,” SAE Paper No. 2003-01-1463, SAE Noise and Vibration Conference, May 2003, Traverse City. Van Karsen, C., Dehlin, C.A.,“Development of a Six Deggree of Freedom Multiple Axis Shaker,” 21th International Modal Analysis Conference, Kissimmee, Feb 2003, Paper #39.Van Karsen, C., Mouw, N., “Time and Frequency Domain Instantaneous Center Locator Methods with Applications,” 21th International Modal Analysis Conference, Kissimmee, Feb 2003, Paper #10.Derk, J., Van Karsen, C., Knox, K. J., “Experimental Verification of a Gear Noise Model”, 20th International Modal Analysis Conference, Los Angeles Ca., Feb 2002.Blough J.R., “A Survey of DSP Methods for Rotating Machinery Analysis, What is Needed, What is Available”, Special Edition of Journal of Sound and Vibration from India-USA Symposium 2001 – Emerging Trends in Vibration and Noise Engineering. Volume: 262, Issue: 3, pp. 707-720, May 2003.Kowalski D., Rao M.D., Blough J.R., and Gruenberg S., “Dynamic Testing of Shock Absorbers under Non-Sinusoidal Conditions”, Journal of Automobile Engineering. Proc. Institution of Mechanical Engineers, vol. 216, Part D: Journal of Automotive Engineering, pp. 373-384, 2002.

Contact InformationContact Information

Jason Blough (jrblough@mtu.edu) - (906) 487 1020

Mohan Rao (mrao@mtu.edu)– (906) 487 2892

Chuck Van Karsen (cdvankar@mtu.edu) –(906) 487 2159

www.me.mtu.eduME-EM DepartmentMichigan Tech University1400 Townsend Drive333Houghton, MI 49931Ph: (906) 487-2551Fax: (906) 487-2822

Jason BloughJason Blough

ME-EM NVH Faculty

Harold EvensenHarold Evensen

ME-EM NVH Faculty

Gordon ParkerGordon Parker

ME-EM NVH Faculty

Chris PasserelloChris Passerello

ME-EM NVH Faculty

Mohan RaoMohan Rao

ME-EM NVH Faculty

Chuck VanKarsenChuck VanKarsen

ME-EM NVH Faculty