novomec-vehicle nvh · pdf filecontributionsnvh development on different actions product...

Vehicle NVH Development

www.novomec.com [email protected] Tel: +90 216 7061324 Fax: +90 216 70612841

Contributions on Different Product Development PhasesNVH Development Phases

New Vehicle Product Development Actions

Existing Vehicle Ongoing Product Development Actions

Quality Improvement

Customer Complaint Troubleshooting

Cost Reduction

Manufacturing Quality Monitoring

Benchmark & Target Setting

Development & Target Achievement

Design Verification & Vehicle Sign‐off

Novomec Engineering provides consultancy and hands‐on project services throughout the complete vehicle development phases.


Contributions on Different Product Development PhasesNVH Development Actions

Pre‐Program NVH Development Actions

Virtual Prototype CAE‐based NVH Development

Physical Prototype Test‐based NVH Development

NVH Status Identification & Development Iterations

Component‐induced NVH Problem Solving

Vehicle Isolation & Acoustic Pack Development

Vehicle Wind Noise Assessment & Development

Statistical NVH Quality Monitoring of Production Vehicles

Noise Source Contribution & Transfer Path Analysis


Contributions on Different Product Development Phases

1) Vehicle NVH Benchmarking

2) Vehicle Level Target Setting & Cascading

3) Establishing NVH Development Action & Time Plan to Achieve Targets

4) NVH Trainings

PRE‐PROGRAMNVH DEVELOPMENT ACTIONS


VEHICLE NVH BENCHMARKING

Target Development Vehicle Competitor 1 Competitor 2 Competitor 3

Overall Level 8,0 18,3 10,1 4,8 4,6

H476 Target

Vibration in RMS (mm/s)

Steering Wheel Vibration

0

5

10

15

20

Target Development Vehicle Competitor 1 Competitor 2 Competitor 3

Overall Level

SCOPE: NVH status identification of competitor vehicles by objective NVH testing indifferent operating conditions (Acceleration, PT, WOT, Cruise,Idle, etc...)

ACTION: Objective NVH Testing and Data Analysis: Interior Noise Overall Level 1/3 Octave Spectrum Articulation Index (Psychoacoustics) Steering Wheel Vibrations Seat Track Vibrations


VEHICLE NVH BENCHMARKING

SCOPE: Subjective NVH rating of all benchmark vehicles inline with SAE J 1060 J2

ACTION: Trained NVH observes assess the vehicle and evaluate all NVH attributes (P/T, Road, Wind NVH)

1 2 3 4 5 6 7 8 9 10

Attribute Performance

Borderline Acceptable Fair Good Very Good Excellent

Customer Perception

Somewhat Dissatisfied

Very Satisfied

Perceptible ByNot

Perceptible

Not Acceptable

Very Dissatisfied

All Customers Average Customer Critical Customer Trained Observer

Fairly Well Dissatisfied Completely Satisfied

Poor

? All signal state and error state issues are determined and rated according to the severity scale

(SAE J 1060 J2).Novomec holds the «SubjectiveVehicle Evaluation and RatingCertificate» given by Ford MotorCompany Belgium.


NVH TARGET SETTING & CASCADING

SCOPE: Vehicle level NVH target setting and target cascading.

Target cascading to sub systems and design teams.

B = Best in Class A = Amongs the Leaders C = Competitive U = Uncompetitive

?

Setting objective vehicle level NVH targets based on company vision and targets in the market

ACTION: Determination of the existing products NVH levels against its competitors


NVH DEVELOPMENT ACTION PLANNING

SCOPE: Establishing a vehicle development time and action plan with the client

Planning of NVH CAE ActionsCAE

• Partial Model• Full Vehicle Model• CAE Target Book & Analysis Planning

Planning of NVH Testing ActionsNVH Testing

• Part Requirements• Required Design Team Support• Required Supplier Support

ACTION:


VEHICLE, CHASSIS, POWERTRAN NVH TRAININGS

SCOPE: Giving Vehilce NVH Trainings to team members if required prior to development.

Vehicle NVH Awareness & General Topics Psycho‐acoustics Fundamentals Sound Package and High Frequency NVH Transfer Path Analysis (TPA) NVH Testing & Digital Signal Processing Several Common Vehicle NVH Problem Examples Application on a Vehicle

By F. Okan TandoganNovomec Engineering, Istanbul/TURKEY

Principles of NVH Wheel, Brake & Tire NVH Driveline NVH Engine NVH Isolator Behavior Isolator Design Isolation Strategies High‐end Isolators Torsional Vibrations Hybrid and Electrical Vehicle NVH

By Mark DalyNVH Experts, Michigan/USA

VEHICLE NVH TRAINING CHASSIS AND POWERTRAIN NVH TRAINING


1) Creating Full Vehicle NVH CAE Model

2) Vehicle Modal Alignment

3) Sub‐system Modal Separation

4) Powertran Modal Alignment

5) Modal Contribution Analysis

6) Panel Contribution Analysis

7) Trim Body Structural Analysis

8) Design Iterations for NVH Problems (Hybrid approach using test data)

VIRTUAL PROTOTYPE CAE‐BASED NVH DEVELOPMENT


Analysis Pre‐Processor Solver Post‐processor Outcome

Modal Analysis

HypermeshANSA

NastranRadioss

Hyperview, Meta•Resonance Frequencies•Damping• Mod shapes

Frequency Response Functions

HypermeshANSA

NastranRadiossVirtual Lab

Hypergraph, Virtual Lab Determination of the dynamic behavior of structures under transient input in frequency domain(NTF, VTF, IPM)

Transient Response Analysis

HypermeshANSA

NastranRadioss

Hypergraph Determination of the dynamic behavior of structures under transient input in time domain



CAE NVH Capabilities

Analysis Pre‐Processor Solver Post‐processor Outcome

Coupled fluid‐structure Analysis

HypermeshANSASofy

NastranCoupled fluid‐structure noise analysis

Virtual Lab

Modal Contribution Analysis

HypermeshANSA

NastranRadioss

Virtual Lab

Determination of different modes’ contribution on the response of structures in different frequencies.

Panel Contribution Analysis

HypermeshANSA

NastranRadioss

Determination of panels’ contribution on the response of structures in different frequencies.

Virtual Lab



1) Prototype Vehicle NVH Status Identification vs. Targets

2) NVH Development Iterations on Prototypes

3) Root Cause Identification of Component‐induced Vehicle NVH Problems

4) Vehicle Interior Noise Source Contribution & Transfer Path Analysis (TPA)

5) Vehicle Isolation Strategy & Acoustic Pack Development

6) Wind Noise Assessment & Development

PHYSICAL PROTOTYPE TEST‐BASED NVH DEVELOPMENT


SCOPE: Determine the NVH performance of the prototype compared to the targets setat the beginning of the vehicle program

STATUS IDENTIFICATION AGAINST TARGETS SET


SCOPE: The planned development actions (new designed parts, structural modificationsetc.) are installed in the vehicle and tested to figure out the NVH performance.

Design #2

Design #3

Design #5Design #4

Design #1

NVH DEVELOPMENT ITERATIONS ON PROTOTYPE VEHICLE


SCOPE: Determine any component‐induced vehicle NVH problems

ACTION:

Problem Root Cause Identification by NVH Testing

Recommending interim and permanent corrective actions to overcome NVH problems

Setting component level targets to suppliers (Turbo, Differential, etc...)

Setting plant quality monitoring procedures for manufacturing NVH quality

COMPONENT‐INDUCED NVH PROBLEMS


Air-borne and structure-borne Intake Orifice Noise

Axle whine, axle grinding... Other exctation sources

Steering system noises(moan, hiss, grunt...)

Transmission gear rattle, gear whine

Engine accessory whines

Turbo whine, whistle, whoosh, spool, blow-off, rattle...

Exhaust rush noise



Examples:Measurement of Turbo‐induced noise and correlation

Subjective assessment and definition of any vehicleNVH problem.

Characterization of the problem by means of NVHtesting.

Evaluation of operational inputs and structuralsensitivity.

Development iterations and problem solving.



Example #1


Noise Problem

Problem Solved


Example #2


Turbo Noise 2

Turbo Noise 1

Interior Noise Spectrum

Turbo Noise 1

Turbo Noise 2

Spectrum of the Noise Source

Noise correlation studies to determinethe root cause of the component‐induced NVH phenomena


NOISE SOURCE CONTRIBUTION AND TRANSFER PATH ANALYSIS (TPA)

SCOPE: Determine the contribution of each noise source and path on overall interiornoise.ACTION: A variety of different vehicle and sub‐system level NVH measurements are carried out. TPA model is created using the test‐based data.

Measured Noise Calculated Noise by TPAAIR‐BORNE

Engine/Exhaust/Intake Radiated Noise [dB(A)]

‐

Engine Noise Reduction [dB(A)]

STRUCTURE‐BORNE

Engine/Exhaust/Intake Structure‐borne Excitation [N]

x

Noise Transfer Function [dB(A)/N]

+


itikt HFvv /. itikt HFPP /.

Partial Vibration Partial Sound Pressure



Yapısal‐Taşınımlı Gürültü Katkısı

Noise and Vibrations Transfer Functions are Measured

Noise Transfer FunctionA

Reference Input ForceA

Interior Noisex =



Examples: Transfer Path Analysis (TPA)NOISE SOURCE CONTRIBUTION AND TRANSFER PATH ANALYSIS (TPA)

Semi‐anechoic chassis dyno having a maximum cut off frequency of 100 Hz required

STRUCTURE‐BORNE CONTRIBUTION1. Input Point Mobilities (IPM)2. Noise Transfer Functions (NTFs)3. Vibration Transfer functions (VTFs)4. Operational Accelerations5. Forces on Attachment points

AIR‐BORNE CONTRIBUTION1. Volume Velocity Transfer Function (VVTF)2. Engine radiated noise (High Frequency)3. Operational Exhaust Radiated Noise4. Operational Intake Radiated Noise

VEHICLE NOISE REDUCTION MEASUREMENTS1. Engine Noise Reduction (ENR)2. Intake Orifice Noise Reduction (IONR)3. Exhaust Orifice Noise Reduction (EONR)4. Tire Patch Noise Reduction (TPNR)


Operational intake and exhaust system radiated noise measurements for TPA model



Sonuçlar

Determination of Vehicle Local High Frequency Air‐borne Acoustic Sensitivity vs. Frequency

GirişTerminolojiNVH Geliştirme SüreçleriNOISE SOURCE CONTRIBUTION AND TRANSFER PATH ANALYSIS (TPA)


Source 4 – 4th EO Contribution




Total 4th EO Contribution

Soun

d Pressure Level [d

B(A)]

Engine Speed [rpm]

Soun

d Pressure Level [d

B(A)]

Engine Speed [rpm]


Sub Systems % Noise Contribution


Süspansiyon #1 – Kuvvet, NTF, 4. Mertebe İç Gürültü Katkısı

Force

NTF

X

Detailed Noise Source Contribution

Highest % contributor is investigated in more details



Studies for Interior Noise DevelopmentVEHICLE ISOLATION &ACOUSTIC PACK DEVELOPMENT

1) Setting Vehicle Isolation Strategy & Targets

2) Vehicle Acoustic Pack Development and Verification


Studies for Interior Noise Development

Ultrasonic Leakage Detection

SCOPE: Determining vehicle isolation status; setting isolation strategy and targets

ACTION: Body in Prime Air Leakage Testing & Target Setting

(Determination of the sealing performance between sheet metal flanges) Full Vehicle Air Leakage Testing, Contribution Analysis and Target Setting

(Determination of sealing performance of trimmed body) Ultrasonic Measurements to Determine Weak Leakage Points.

VEHICLE ISOLATION &ACOUSTIC PACK DEVELOPMENT


Barriers Damping Material Absorber Material


SCOPE: Examining vehicle acoustic pack stragety and development if required.

ACTION: Vehicle concept acoustic pack requirements are determined based on competitive benchmark

and vehicle targets. Sub‐system (Noise Reductions) and vehicle level prototype testing is conducted to determine

the status. Iterations with different acoustic pack are conducted and the achieved development is

reported via sub‐system and vehicle level testing.


Depending on the weakness of the vehicle in terms of air‐borne noise (engine/road/wind) the mostsuitable acoustic materials are recommended and verified via objective NVH testing



Examples: Acoustic Pack Development

Objective Comparison of Sound Pack Development Iterations

Component level comparison atacoustics labs (if available).

System level comparison by wayof vehicle local noise reductionmeasurements.

Vehicle level comparison byoperational data and psychoacoustics analysis.



Studies for Interior Noise DevelopmentVEHICLE WIND NOISE ASSESSMENT AND DEVELOPMENT

ON‐THE‐ROAD DIAGNOSTICS

A drive team of 2‐3 engineers evaluate the vehicle on the road for wind noise Objective data can be collected for wind noise (ambient wind conditions are important!) Sthetoscope can be used in localization of wind noise issues

WORKSHOP DIAGNOSTICS

Leakage tests can be performed to localize weak spots (air leakage, ultrasonic tests etc.)

WIND TUNNEL DIAGNOSTICS

Being the best approach, vehicle can be tested in a wind tunnel if available for development A test roadmap can be created to pinpoint wind noise contributions


Studies for Interior Noise DevelopmentVEHICLE WIND NOISE ASSESSMENT AND DEVELOPMENT

Wind Noise Contribution Analysis


Studies for Interior Noise DevelopmentSTATISTICAL NVH QUALITY MONITORING OF PRODUCTION VEHICLES

LIST OF NVH QUALITY MONITORING ACTIONS:

1) Determination of Vehicle Specifications

2) Establihing a Test Approach & Releasing Test Procedures

3) Determination of NVH Testing Period

4) Operator Training

5) Gage R&R Studies to Identify Repeatability

6) Statistical NVH Analysis forMonitoring Manufacturing Quality

7) Examination of Individual Production Vehicles Against Manufacturing Problems



ACHIEVEMENTS FROM NVH QUALITY MONITORING STUDY:

1) Periodical evalution of manufacturing vehicles’ NVH built quality

2) Manufacturing related problems can be reported objectively

3) Corrective action plans can be released for manufacturing lines

4) Statistical NVH database can be used in development & cost reduction studies

5) Customer units can be kept within a certain target noise band



Determination of noise distribution of manufacturing vehicles 10%, 50%, 90% percentiles and average.


novomec-vehicle nvh · pdf filecontributionsnvh development on different actions product...

Documents