Part 9_NVH Methodology

NVH
Methodology
NVH Course
pg 1
NVH
Total Vehicle System
Engine Wheel & Tire Unbalance
Steering Wheel Shake Seat Vibration
Road Input Accessories Environmental Sources
Rearview mirror vibration Noise at Driver’s & Passenger’s Ears
Input
NVH Course
System
pg 2
Output
ACOUSTIC
VISUAL
TACTILE
1

The Conceptual Model for NVH Phenomena
Loads
X
System Transfer
Response
Force Force
Structural-structural Structural-structural
Vibration Vibration
Structural-acoustical Acoustical-structural Acoustical-structural
R = Σ Hii Lii
Noise Noise
Vol. Vol. Velocity Velocity
Acoustical-Acoustical Acoustical-Acoustical
NVH Course
pg 3
Forms of the FRF function for mechanical systems
Response Parameter R
Standard FRF: R/F Receptance Admittance Dynamic Compliance Dynamic Flexibility Mobility
Inverse FRF: F/R
Displacement
Dynamic Stiffness
Velocity
Impedance
Acceleration
Accelerance Inertance
Apparent Mass Dynamic Mass
NVH Course
pg 4
2

The Input-Transfer- Response Model for NVH
airair-borne
Wsource
Pinterior
structurestructure-borne
Pexterior
vsource
F
vstructure Transfer
Medium Acoustical
Input
Acoustical Mechanical
Response
Structure
Surface
NVH Course
pg 5
Technologies for NVH
Input
Acoustical Mechanical
Transfer
Medium Structure
Surface
Response
Acoustical Vibration Spectral Analysis Signature Intensity Sound Quality
Experimental Assessment
Spectral Analysis Signature Operational Defl.
Holography
FRF Analysis TPA (structure-borne)
Experimental Modeling
ASQ (air-borne)
Modal Analysis Vibro-acoustic Modal Analysis FRF Based Modeling ESEA Acoustical FEM MBS (Structural FEM) VIOLINS SEA BEM Ray Tracing
Numerical Modeling
NVH Course
pg 6
3

Behavioral Characterization
? Distributed physical properties
Stiffness…Mass…Damping
? Vibration Modes as basis for dynamic characteristics
? Low ? Large ? Low “Global Modes” Modes” frequency wavelength modal density high small high “Local Modes” Modes”
NVH Course
pg 7
Behavioral Characterization
Low frequency 0-100 Hz
Global shape GlobalModes Modes shape& &eigenfrequency eigenfrequency Body I I& Body &IIIIBending Bending I I& &IIIITorsion Torsion Cavity Cavity 0-250 0-250Hz Hz point-to-point point-to-point over overfrequency frequency
Transfer TransferBehavior Behavior Medium frequency 100100-250 Hz
Point PointMobility Mobility Vibration Transfer Vibration TransferFunction Function Noise Transfer Noise TransferFunction Function Energy EnergyFlow Flow component component @ @ frequency frequencyrange range
High frequency >250 Hz
NVH Course
pg 8
4

Process Interactions
Program
Pre-Program
Definition
Program Phase
Production
Styling
CAD/DMU
Package Lay-out
Design Feasibility
3
CAE/CAT
Function Production Concept Performance Performance Performance Crash - Ride & Handling - Durability - NVH - Manufacturability & Assembly
2
CAE-Process
Simulation Steps
CAT-Process
1 Test Steps
NVH Course
pg 9
CAE – CAT Interaction
Program
Pre-Program
Definition
Program Phase
Production
Styling
CAD/DMU
Package Lay-out
Design Feasibility
CAE/CAT
Function Production Concept Performance Performance Performance Crash - Ride & Handling - Durability - NVH - Manufacturability & Assembly
CAE-Process
Simulation Steps
CAT-Process
Test Steps
NVH Course
pg 10
5

CAE and CAT Process Positioning
CA
PA
DE
SB
Architecture
Concept Design Verification Feedback, Assessment & Corrective Action
Digital Product Development CAE CAT
“Validation of Function & Specifications” “Test Planning”
Physical Product Development
“Verification of Simulation with Test results” “Validation of Test Hardware”
NVH Course
pg 11
CAE and CAT Process Positioning
CA
PA
DE
SB
Architecture
Concept Design Verification Feedback, Assessment & Corrective Action
Digital Product Development
Physical Product Development
CAE
CAT
NVH Course
pg 12
6

Reverse-Engineering Actual System Behavior
Loads
X
System Transfer
Response
Modeling
Assessment
CAT
Model Identification
Experimentally
NVH Course
pg 13
Physical Prototype Refinement
VII
II
Validated Product Design
Qualified Product
Design Validation
Component Manufacture System Assembly Response Observation Response Assessment
VI V IV III
Operation
Design Improvement
Engineering Judgement
NVH Course
pg 14
7

Forward-Engineering Projected System Behavior
Loads
X
System Transfer
Response
Modeling
Assessment
CAT
Model Identification
Experimentally Response Simulation
Numerically
CAE
NVH Course pg 15
Virtual Prototype Refinement
VIII
VII
Balanced Design Concept
Validated Product Design
Design Validation
Component Modeling System Synthesis Response Simulation Response Assessment
Yes
OK
No
Loads
Design Optimization
Optimization
NVH Course
pg 16
8

Forward-Engineering Projected System Behavior
Loads
X
System Transfer
Response
Modeling
Hybrid
Assessment
CAT
Model Identification
Experimentally Response Simulation
Numerically
CAE
NVH Course pg 17
The Hybrid Approach for NVH Engineering
CAE Component Models Component Models Component Validation Models Component Correlation Modeling
Updating
Loads
System Loads Synthesis System Response Low-Mid-High Synthesis Simulation Frequency Loads
Response Assessment
Yes
OK
No
Component Models Test
Loads
Optimization
NVH Course
pg 18
9

Reverse-Engineering Wanted System Behavior
Loads
X
System Transfer
Response
Modeling Experimental Design Synthesis Numerical
Assessment
Target Response
NVH Course
pg 19
CAE and CAT Process Positioning
CA
PA
DE
SB
Architecture
Concept Design Verification Feedback, Assessment & Corrective Action
Digital Product Development
Physical Product Development
CAE
CAT
NVH Course
pg 20
10

Attribute CAE Interaction
Program
Pre-Program
Definition
Program Phase
Production
Styling
CAD/DMU
Package Lay-out
Design Feasibility
CAE/CAT
Function Production Concept Performance Performance Performance Crash - Ride & Handling - Durability - NVH - Manufacturability & Assembly
CAE-Process
Simulation Steps
CAT-Process
Test Steps
NVH Course
pg 21
Multidisciplinary Leverage
Process Stages Gas Flow / Charge
Functional Performance Factor Power Emissions Economy Gas Forces Assembly Motion Distribution Balancing Reaction Forces Internal Forces Component Mechanics Static Strength Durability Eigenbehavior
Core Engine
Combustion
Operation Dynamics
Mass Forces
Structural Integrity
System Synthesis
Transfer Behavior Transfer Behavior
Structural Dynamics
Pressure Loading External Forces Surface Radiation Volume Acoustics Structureborne excitation Airborne Emission Intake & Exhaust Noise
Noise & Vibrations
NVH Course
pg 22
11

The CAE Process for engine N&V
Modeling Modeling System System
FE-Track FE
Modeling Modeling Components: Components:
?Single ?Single component component ?System-assembly ?System-assembly ?Joints ?Joints ?Coupling ?Coupling Peripherals Peripherals
Modeling Modeling System System Excitation: Excitation:
?Combustion ?Combustion ?Cranktrain ?Cranktrain ?Valvetrain ?Valvetrain ?Chain ?Chain Drive Drive
MBS-Track MBS-
System System Simulation Simulation Model Model Updating Updating System System Transfer: Transfer:
Structure-borne Structure-borne Air-borne Air-borne
System System Excitation: Excitation:
Force Force Identification Identification
System System Responses: Responses:
Operating Operating Vibrations Vibrations Operating Operating Noise Noise
Result Result Validity Validity
NVH Course pg 23
Goals for Crank Train Simulation
Crank Train Dynamics
? ? ? ? ?
Bearing Performance Loads (bearings, mounts,etc.) Structural vibration Dynamic stresses Acoustic radiation
Applications:
? ? ? ? ? ?
Balancing Strategies Mount optimization (idle shake) Noise radiation (pass-by regulation) Crank/block stress distributions Fatigue Assessment Bracket Location Assessment
NVH Course
pg 24
12

Crank Train Application with LMS https://www.sodocs.net/doc/682811540.html,b Motion
Gas Forces applied
NVH Course
pg 25
Crank Train Application with LMS https://www.sodocs.net/doc/682811540.html,b Motion
Rigid Body Application
NVH Course
pg 26
13

Crank Train Application with LMS https://www.sodocs.net/doc/682811540.html,b Motion
Making the crankshaft flexible 9Meshing available within https://www.sodocs.net/doc/682811540.html,b Motion 9Define Rigid Virtual Parts 9Define Static and Normal Mode Loadcases and solve 9Orthonormalize modes in LMS https://www.sodocs.net/doc/682811540.html,b Motion 9Edit Modes - Add Modal Damping…
NVH Course
pg 27
Crank Train Application with LMS https://www.sodocs.net/doc/682811540.html,b Motion
NVH Course
pg 28
14

Load Identification with LMS https://www.sodocs.net/doc/682811540.html,b Motion
9Visualize Deformations 9Visualize Stresses 9Find more accurate results
9Motion 9Forces
9Repeat for Block
NVH Course
pg 29
Performance Information
Inline 6-cylinder example ?Block has 27669 nodes, 26045 elements, 61 modes ?Crank has 6276 nodes, 4425 elements, 49 modes
Solution finishes in < 5 minutes (294 CPU sec, on HP J5000)
4.3L V6 example ?Block has 32551 nodes 23968 elements, 63 modes ?Crank has 6042 nodes, 4114 elements, 49 modes
Solution finishes in 9 minutes (572 CPU sec, on PIII 600 MHz)
Both models run at 4000 rpm w/combustion loads, for 6 revolutions NVH Course pg 30
15

Enhanced EHD Hydrobearing – complete process
Block-Crank spatial DoF’s Block-Crank sensor FE nodes Block-Crank surface nodes composite FE surface bearing mesh mapped force/torque pressure vector field force/torque oil-to-FE mesh summation mapping oil mesh pressure field per-node clearance rigid sleeve clearance+rate
exact clearances at each FE surface node
geometry FE-to-oil mesh calculation mapping
oil oil mesh mesh calculated mapped clearance field
Oil Mesh Pressure Calculation (Boedo)
NVH Course
pg 31
Enhanced EHD Bearing Model
?
To accurately respond to surface pressure, 15 static “attachment” modes are calculated at each journal ? 5 circumferential shapes: const., sin(θ), cos(θ),sin(2θ), cos(2θ) ? 3 axial shapes: const., sin(π/L·z), cos(π/L·z) ? 15 total combined modes (all possible products of axial and circumferential shape functions) Experience to date shows this 5x3 mode space should be sufficient for any reasonable loading of the journal, but additional attachment modes can be created if desired (7x3,9x3,…)
?
NVH Course
pg 32
16

0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
-1.0000 0.0000 0.5000 1.0000
-0.5000
-1.0000
-1.0000 -0.5000
-0.5000 0.0000
0.0000 0.5000 1.0000
0.5000
1.0000
0.0
0.0 30.0 60.0
0.0 30.0 60.0
Theta
0.0 30.0 60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 Theta
30.0 60.0 Theta
Theta
90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0
90.0
90.0 120.0 150.0
120.0 150.0 180.0
180.0 210.0 240.0 270.0 300.0 330.0
330.0
360.0 -0.50 -0.25 0.00 Z 0.25
NVH Course
210.0 240.0 270.0 300.0 330.0 360.0 -0.50
NVH Course
360.0 -0.50
360.0 -0.50 -0.25 0.00 Z 0.25 0.50
-1.0000 -0.5000 0.0000 0.5000 1.0000
-0.25
-0.25 0.00 Z 0.25
0.50
0.00 Z 0.25 0.50
0.50
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
-1.0000
-0.5000
-1.0000
-0.5000
0.0000
0.5000
1.0000
0.0000
0.0 30.0 60.0 90.0 120.0
0.5000
1.0000
0.0 30.0 60.0 Theta 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0
0.0 30.0
Theta
T he t a
60.0 90.0 120.0
150.0 180.0 210.0
270.0
300.0
300.0 330.0
360.0 -0.50 -0.25
Theta 150.0 180.0 210.0
240.0 270.0
240.0
330.0 360.0 -0.50 -0.25 0.00 Z 0.25 0.50
360.0 -0.50 -0.25 0.00 Z 0.25 0.50
Z
0.00 Z 0.25 0.50
-1.0000 -0.5000 0.0000 0.5000 1.0000
-1.0000
-0.5000
0.0000
0.5000
1.0000
-1.0000
-0.5000
0.0000
0.5000
1.0000
-1.0000 0.0000 0.5000 1.0000
-0.5000
EHD Pressure Shape Functions (5x3)
Example EHD Orthogonalized Mode Set
0.0
0.0 30.0
60.0 Theta
pg 34
0.0 30.0
30.0 60.0 90.0 0.0
pg 33
90.0 120.0
120.0 270.0 300.0 330.0 360.0 -0.50 -0.25 Theta 150.0 180.0 210.0 240.0
30.0 60.0
Theta
60.0 Theta 90.0 120.0
90.0 120.0
150.0
150.0
150.0
180.0
180.0
180.0
210.0
210.0
210.0
240.0
240.0
240.0
270.0
270.0
270.0
300.0
300.0
300.0
330.0
330.0
330.0
360.0 -0.50 -0.25
360.0 -0.50
360.0 -0.50 -0.25
Z
-0.25
0.00 Z
0.00
0.00
0.00 Z
0.25
Z 0.25 0.50
0.25
0.50
0.25 0.50
0.50
-1.0000
-0.5000
0.0000
0.5000
1.0000
-1.0000
-0.5000
0.0000
0.5000
1.0000
0.0
-1.0000 0.0 30.0 60.0 Theta 270.0 300.0 330.0 360.0 -0.50 -0.25 0.00 Z 0.25 0.50 90.0 120.0 150.0 180.0
-0.5000
0.0000
0.5000
1.0000 Theta 120.0 150.0 180.0 210.0 210.0 240.0 240.0 270.0 300.0 330.0 360.0 -0.50 -0.25 0.00 Z 0.25
0.0 30.0
Theta
30.0
60.0 90.0
60.0 90.0 120.0 150.0 180.0 210.0 240.0 270.0 300.0 330.0 360.0 -0.50 -0.25 0.00 Z 0.25 0.50
0.50
17

Detailed modeling and analysis for N&V
Integrated V5 Environment: CATIA V5 Analysis and LMS https://www.sodocs.net/doc/682811540.html,b
Design Office
CAE Office
Surface meshing Acoustic radiation calculation Acoustic postprocessing
user6
Part1 Meshing
user1
Modes Part2 Meshing FEM Assembly FunctionFunction-based assembly Modes FunctionFunction-based analysis Vibration postprocessing
user2
Non associative Mesh
user5 user3
Nastran file
Test file
Test-based model
user4
Component loads
Engineering Hub NVH Course
Simulation Hub
DS LMS
pg 35
3rd party
Synthesis Methods
FE Input FE model of each component CAE Rigid, spring/damper FE model of assembly Modal uncoupled modes of each component CAE + Test Rigid, spring/damper Modes of the assembly FRF Uncoupled FRFs of each component CAE + Test Rigid, spring/damper, dynamic stiffness FRFs of the assembly and the force transmissibility
Source Coupling Output
Benefit
? # DOF can be reduced without loss of information ? # modes << # freq lines ? Fast calculations
? Reduced model size ? ? Fast calculations ? Higher frequency range
compared to modal model
? Frequency dependent
coupling supported Solver Nastran, ANSYS, Elfini, … LMS https://www.sodocs.net/doc/682811540.html,b LMS https://www.sodocs.net/doc/682811540.html,b
NVH Course
pg 36
18

Speeding up FE calculations of assemblies
? Represent invariant components by Test model ? Convert Test-based modal model into equivalent “FE
model”
? Assemble and solve full system in FE ? Avoid pure modal or FRF assembly if FE calculation
step is needed for every iteration
? Replace FE model of invariant components by reduced
modal model ? Modal model from FE component analysis as part of assembly model ? Significantly speed up calculation of system model
÷ 60
8 hours CPU 8 minutes CPU
NVH Course
pg 37
How to determine coupling stiffness of bolts?
? Determine contact area + use rigid connections in this area
Non-linear FE analysis Use pressure sensitive paper ? FE/experimental correlation ? Create updated FE models of both components ? Do modal analysis on assembly ? Update connection properties FE model to match experimental model
? ?
Thickness flange
2.0
t=2.3mm
Reaction force (N)
1.5 1.0 0.5 0.0
t=4.6mm t=6.9mm t=9.2mm t=11.5mm
-0.5 5.0
contact area 17.0 (mm) 9.0 11.0 13.0 15.0 19.0 21.0 7.0 Radius
NVH Course
pg 38
19

Detailed modeling and analysis for N&V
Integrated V5 Environment: CATIA V5 Analysis and LMS https://www.sodocs.net/doc/682811540.html,b
Design Office
CAE Office
Surface meshing Acoustic radiation calculation Acoustic postprocessing
user6
Part1 Meshing
user1
Modes Part2 Meshing FEM Assembly FunctionFunction-based assembly Modes FunctionFunction-based analysis Vibration postprocessing
user2
Non associative Mesh
user5 user3
Nastran file
Test file
Test-based model
user4
Component loads
Engineering Hub NVH Course
Simulation Hub
DS LMS
pg 39
3rd party
Acoustic Modeling: Calculation Strategies
Finite Element Method (FEM) ? Describe acoustic wave equations element by element ? Volume mesh ? Acoustic properties defined per element ? Special “infinite elements” to model free field Boundary Element Method (BEM) ? Project acoustic wave equations on surface elements ? Assumes uniform fluid properties ? Easier to create surface mesh i.s.o. volume mesh ? No special measures needed to model “free field”
NVH Course
pg 40
20