Software for vibro-acoustic analysis and design Product ... · A statistical energy analysis subsystem formulation using finite element and periodic structure theory. Journal of Sound

Copyright © ESI Group, 2010. All rights reserved.Copyright © ESI Group, 2010. All rights reserved.

Software for vibro-acoustic analysis and designProduct/application/research update

Dr. Terence ConnellyMay 9th 2011

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Copyright © ESI Group, 2010. All rights reserved.

OverviewESI Application ExamplesESI Updates

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Overview


What is VA One?

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VA One

Model structure with FE

Model bounded or unbounded fluids with BEM

Model bounded fluids with FE

Couple FE and SEA together for fast models at mid-frequencies

Quick system level models of complex

systems at high frequencies

Extension modules for customization and advanced analysis


Extension Modules

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VA One


VA One release history

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VA One 2007.5

January 2008 August 2008 March 2009 September 2009 April 2010

VA One 2008.0

VA One 2008.5

VA One 2009

VA One 2010

49 enhancementsStress module,

Periodic module, Perforated NCTs, BEM Grid solver +

…

45 enhancementsFast Multipole BEM

, Multi-domain BEM, SEA productivity

64 bit scripting + …

38 enhancementsEnhanced junctions + isolators,

Complex loads/BC + …

30 enhancementsSpecial release

focused on FOAM finite elements [integration of

Rayon VTM solver into VA One]

80 enhancementsGeneral

enhancements to all modules.

Theme = contribution analysis and methods to diagnose response.

April 2011

VA One 2010.5

Focused on

-Squeak and Rattle

- Aero-vibro-acoustics- General

Enhancements

Current release

6 major releases within the past 3 years



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Overview


SEA – High Frequency Interior Noise

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Design of Acoustic Insulation in Ships Based on Predictive VA Models, Blanchet et al,

DAGA 2011

‘SEA in the real world’J. Venor, Audi Euronoise 2009

SEA Interior Noise Validation for Rotorcraft, D.J.Butts , AHS Aeromechanics Conf 2008

Interior Noise YachtsInterior Noise Rotorcraft

Interior Noise Cars


Mid FrequencyHybrid FE-SEA

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“Modeling process and validation of Hybrid FE-SEA method for structure-borne noise paths in a trimmed automotive

vehicle”. A. Charpentier et al, Proc. SAE NVH Brazil, 2008Noise and Sound Quality Optimization of Agricultural

Machine Cab, Cerrato, Connelly et al, SAE 2010 paper ‘Vibro-Acoustic Hybrid Modeling and Analysis of the ARES IX Roll Control System’, B.Prock, SCLV 2008

SBN in Launch Vehicles

SBN Automotive SBN /ABN Agricultural Cabs

Copyright © ESI Group, 2010. All rights reserved.10

dB

Low FrequencyFE-BEM

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100 125 160 200 250 315 400 500 630 800 1000 1250

Frequency (Hz)

SPL

(dB

ref.

2E-5

Pa)

Measured

SEA model - exp. exterior noise

SEA model - num. exterior noise

5 dB

T. Connelly, Kent Fung “Validation of Interior noise prediction obtained using SEA and Fast Multipole

BEM”. Proc. SAE N&V, 2009

Engine Radiated NoiseExterior Sound Fields

Low-Mid freq engine noise project

Vehicle Interior Noise due to TBL

A.Businger, M.Eberle et al, “Computation of underbody flow aero-acoustics for a production

vehicle, ESI Global Forum 2010



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Overview


Recent AcquisitionsStrategic investments in CFD and VA

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What’s new in VA2010.5 ?

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Copyright © ESI Group, 2010. All rights reserved. 13

BSR = Buzz, Squeak and Rattle

Products assembled from components

(low frequency random) vibration causes impacts between components

Impacts generate (broadband) force and (broadband) radiated noise

If noise heard by consumer, causes negative perception of product quality

BSR consistently ranked by consumers as one of top quality issues

BSR is an acoustically perceived quality attribute (acoustics is important)

Why use VA One for modeling BSR?Integrated environment for low frequency random vibro-acoustics

Unique methods for impact probabilities and (broadband) force prediction

Unique methods for (full spectrum) acoustic radiation/sound quality

What is “BSR”?


Why is BSR important?

Top 5 consumer complaints

2006 Toyota Tundra 2008 Hummer H2

Top 3 consumer complaints

BSR ranked as one of top consumer complaints for new vehicles [JD powers consumer reviews : www.jdpower.com]


Modeling BSR in VA One

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[1] P. J. Shorter, V. Cotoni, S. Chaigne, R. Langley, “Predicting the Acoustics of Squeak and Rattle”, SAE N&V Conference, Grand Rapids 2011


Example # 1 : clamped beamShaker

(random force 20-400Hz)

Stationary impact hammer(Used to investigate effect of different local

material properties on sound radiation)


Example # 1 : clamped beam

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Movie file : Clamped_beam.avi


Tip material

VA One SPL prediction [dB]

VA One Loudness prediction [sone]

Audible in predictions?

Audible in test?

Steel 66 19 Yes Yes

Plastic 48 5 Just Just

Rubber 36 0.7 No No

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VA One 2010.5 BSR model

Force

Contact

VA One prediction of SPL vs tip material matches test result


Example # 2 : two bolted plates

Shaker (random force 20-400Hz)

Overlapping bolted plates(Look at effect of different bolt locations and different

force levels applied to shaker)


Example # 2 : two bolted plates

Movie file : Bolted_plates.avi


Small force Large force

Configuration 2Bolted on

edges

VA One prediction= no rattle

VA One prediction= no rattle

Configuration 1Bolted on

center

VA One prediction = no rattle

VA One prediction

= rattle

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VA One 2010.5 BSR model

Contact

VA One model predicts configuration and force level that will result in rattle

Point junctions

shakerVA One prediction is impact every 0.8 sec

SPL = 52 dB


Fluctuating Surface Pressure Load

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FE structure Fit equivalent TBL BEM fluid- Apply to FE faces on FE structure- Load can be random or deterministic- FSP load excites structural modes

-Applications : wind noise, impact noise etc.

- Apply to FE faces- Software fits equivalent TBL to data- Use to update parameters of TBL loads applied to FE or SEA subsystems

- Applications : wind noise

- Apply to FE faces on BEM fluid- Load is deterministic- FSP load applies a “compact hydrodynamic pressure boundary condition” to the BEM fluid

-Applications : aero-acoustics

New load in VA One 2010.5. Can be applied to FE faces of FE structural or BEM subsystems. Load defined by pressure time history data

contained in external files. VA One converts to frequency domain.


Journal PapersCotoni, V. and Langley, R.S. and Shorter, P.J. (2008) A statistical energy analysis subsystem formulation using finite element and periodic structure theory Journal of Sound and Vibration, 318 (4-5). pp. 1077-1108. ISSN 0022-460XCotoni, V. and Shorter, P.J. and Langley, R.S. (2007) Numerical and experimental validation of a hybrid finite element - statistical energy analysis method for the harmonic analysis of structure-borne noise Journal of the Acoustical Society of America, 122 (1). pp. 259-270. ISSN 0001-4966Cotoni, V. and Langley, R.S. and Kidner, M.R.F. (2005) Numerical and experimental validation of variance prediction in the statistical energy analysis of built-up systems Journal of Sound and Vibration, 288 (3). pp. 701-728.Langley, R.S. and Cotoni, V. (2005) The ensemble statistics of the vibrational energy density of a random system subjected to single point harmonic excitation Journal of the Acoustical Society of America, 118 (5). pp. 3064-3076. ISSN 0001-4966Shorter, P.J. and Langley, R.S. (2005) On the reciprocity relationship between direct field radiation and diffuse reverberant loadingJournal of the Acoustical Society of America, 117 (1). pp. 85-95. ISSN 0004-4966Shorter, P.J. and Langley, R.S. (2005) Vibro-acoustic analysis of complex systems Journal of Sound and Vibration, 288 . pp. 669-700.Langley, R.S. and Cotoni, V. (2004) Response variance prediction in the statistical energy analysis of built-up systems Journal of the Acoustical Society of America, 115 (2). pp. 706-718.Langley, R.S. and Shorter, P.J. (2003) The wave transmission coefficients and coupling loss factors of point connected structuresJournal of the Acoustical Society of America, 113 (4 (1)). pp. 1947-1964. ISSN 0001-4966Shorter, P.J. and Langley, R.S. (2002) Diffuse wavefields in cylindrical coordinates Journal of the Acoustical Society of America, 112 (4). pp. 1465-1470. ISSN 0001-4966Bremner, P. and Langley, R.S. (1999) A hybrid method for the vibration analysis of complex structural-acoustic systems Journal of the Acoustical Society of America, 105 (3). pp. 1657-1671. ISSN 0001-4966

Conference Papers (recent)2011 6 Papers to date2010 7 Papers2009 8 Papers

Vibro-Acoustics Publications

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Contact Details

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Terence Connelly Ph.D.Lead Acoustics Engineer ESI North America, Inc.

Orchard Ridge Office Building, 32605 W. 12 Mile,Ste. 350, Farmington Hills, MI 48334-3379

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Software for vibro-acoustic analysis and design Product ... · A statistical energy analysis subsystem formulation using finite element and periodic structure theory. Journal of Sound