virtual nvh process with adams/vibration
TRANSCRIPT
Virtual NVHProcess with
ADAMS/VibrationGabriele Ferrarotti
Sr. Industry Manager2001 MDI Japan Users
Conference
Agenda
Two approaches for system-levelTwo approaches for system-levelvibration analysisvibration analysisIntegrating vibration investigation inthe development processAccessing continuous productdevelopment
The Virtual NVH Process
Slower; higher fidelity
Inputs to Mechanical
Model
Post-processingADAMS solution
Time Domain; Physical Space;Fully nonlinear
Time DomainInputs
Plots, animations, & tables and
some frequency data within
ADAMS
NVH data processingwithin I-DEAS Test
Frequency DomainInputs
Frequency Domain;Modal Space;
Linear
Faster; approximate
Slower; higher fidelity
Inputs to Mechanical
Model
Post-processingADAMS solution
Time Domain; Physical Space;Fully nonlinear
Time DomainInputs
Plots, animations, & tables and
some frequency data within
ADAMS
NVH data processingwithin I-DEAS Test
The Time Domain Approach
Standard ADAMS product line as virtualprototyping vibration tool
Independent from physical testingSystem-level approach (opposed to FE-likecomponent approach)ADAMS/Solver enables to take into accountnon linearity effectsCPU time increases proportionally with therequired frequency resolution
The Time Domain Approach
Case Study: Ford Motor CompanyBusiness:Business: Major automotive manufacturer
Challenge:Challenge: Estimate radiated block noise (strongcustomer dissatisfier) caused by sidethrust forces
Solution:Solution: FFT of piston side forces from anADAMS detailed model are used asinput for the NVH analysis in the FEtool to predict sound power level andcorrelate it with measurements
Value:Value: Piston slap noise in different engineconfigurations can be virtually predictedearlier in the design process
The Virtual NVH Process
Slower; higher fidelity
Inputs to Mechanical
Model
Post-processingADAMS solution
Time Domain; Physical Space;Fully nonlinear
Time DomainInputs
Plots, animations, & tables and
some frequency data within
ADAMS
NVH data processingwithin I-DEAS Test
Frequency DomainInputs
Frequency Domain;Modal Space;
Linear
Faster; approximate
Inputs to Mechanical
Model
Post-processingADAMS solution
Plots, animations, & tables and
some frequency data within
ADAMS
NVH data processingwithin I-DEAS Test
Frequency DomainInputs
Frequency Domain;Modal Space;
Linear
Faster; approximate
The Frequency Domain Approach
ADAMS/Vibration add-on product asvirtual prototyping vibration tool
Allows to take your system to differentoperating points to analyze the vibratorybehavior (without having to create newmodels!)Allows various evaluations in modal space,including forced response in the frequencydomain, FRF and mode shape analysis,modal participation factorsValidity within the limits imposed bylinearization approach
The Frequency Domain Approach
Case Study: IsuzuBusiness:Business: Major truck manufacturer
Challenge:Challenge: Create vehicle natural frequency map toinvestigate vibration problemsbypassing the expensive, timeconsuming typical experimentalapproach
Solution:Solution: Development of customized ADAMSenvironment able to allow to reviewfrequency data with the help of a webtool
Value:Value: Accurate evaluation of vehiclevibrations over 50Hz helps to shortendevelopment time and to cut cost
Agenda
Two approaches for system-levelvibration analysis
Integrating vibration investigationIntegrating vibration investigationin the development processin the development processAccessing continuous productdevelopment
Controls
Handling
Durability
Virtual Prototype
Integrated NVH inthe Functional digital Prototype
NVH
Packaging
Typical AutomotiveSystem-Level Scenario
Input (to front wheels):In-phase sine sweep0.8 – 40.0 Hz2mm peak-to-peakdisplacement
Measure: acceleration at3DOF on both sides of allengine mounts. Also atselected points on body.
Graph: response vsfrequency, with phase.
Engine-Mount Manufacturer’s Sensitivity Test
Typical AutomotiveSystem-Level Scenario
In modal space withADAMS/Vibration:
Instantaneouscalculation of FRFsbetween any input andany output to quicklyunderstand vehicledynamicsForced vibrationanimationModal contribution mapfor selected inputchannel and frequency
Typical AutomotiveSystem-Level Scenario
Time
Displacement
Time
Frequency
Acceleration
FFT
In physical spacewith ADAMS/Solver:
Input specified intime domain(frequency sweep)Solution intime domain, using∆t = 0.002, tf = 180secOutput in timedomain (accelerationrequests in theengine mounts)
Typical AutomotiveSystem-Level Scenario
ADAMS time domainresults provided to NVHanalyst in TXT - RPCformatCan be imported intoI-DEAS Test from MTS
Typical AutomotiveSystem-Level Scenario
Observations:Harmonics are due to non-linear components in themodel (bushings, mounts,suspension dampers)
Conclusions:“Modal space analysis”with linearized modelprovides fast qualitativeNVH information“Physical space analysis”with complete non-linearmodel provides higherfidelity NVH information
Typical AutomotiveSystem-Level Scenario
Input:Unbalanced masses(leading and lagging) onright wheel (5 g, 2 cm)
Measure:local rotational velocity atsteering wheel
Graph:Frequency responses
Sensitivity study to springstiffness values
Wheel Out Of Balance (OOB) Analysis
Typical AutomotiveSystem-Level Scenario
Investigate thesteering wheelresonance shift dueto change in springstiffnesses
Additional AutomotiveSystem-Level Scenarios
Random Road Profile AnalysisObserve the PSD response of vehiclecomponents to PSD inputs at the contact patch
Powertrain Out Of Balance (OOB) AnalysisObserve the frequency response of vehiclecomponents to out of balance inputs acting onpowertrain components (i.e. driveline vibrationanalysis)
Agenda
Two approaches for system-levelvibration analysisIntegrating vibration investigation inthe development process
Accessing continuous productAccessing continuous productdevelopmentdevelopment
ADAMS/Vibration 11.0 offers:Frequency domain input forcing functionsFrequency response function calculationsModal participation tablesForced vibration animation
The ADAMS/Vibration Solution
Step 1: Create input channels,output channels, and actuators
Splinedefines
PSD
The ADAMS/Vibration Solution
Define inputs/outputs to beused, operating point,
frequency range, and steps
Step 2: Run Analysis
The ADAMS/Vibration Solution
The ADAMS/Vibration Solution
Step 3: PostprocessingSystem ModesFrequency ResponseFunctionsPower SpectralDensityModal ParticipationTablesNormal ModeAnimationForced VibrationAnimation
The ADAMS/Vibration Solution
ADAMS/Vibration 12.0 offers:Integration with vertical products
Same look and functionalities forADAMS/Standalone and ADAMS/VerticalProduct
The ADAMS/Vibration Solution
ADAMS/Vibration 12.0 offers:Integration with ADAMS/Insight
Dedicated dialog box to create objectivemacros for DOE - A/Insight
The ADAMS/Vibration Solution
ADAMS/Vibration 12.0 offers:Modal energy computation
Energy contribution of each model element inHTML format
Conclusions
ADAMS provides two approachesfor system-level vibration analysisallow complete NVH insight early inthe design processADAMS allows to balancecompeting requirements foroptimum NVH by integrating thevibration investigation in thedevelopment processADAMS continuous productdevelopment guarantees a steadilyimproving solution for your NVHprocess