LMS Virtual.Lab Acoustics
LMS Virtual.Lab Acoustics
Make sound engineering decisions faster
2 LMS Virtual.Lab Acoustics
LMS Virtual.Lab Acoustics 3
LMS Virtual.Lab Acoustics
Makes sound engineering decisions faster
Are your customers expecting ever quieter products? Are your competitors gaining ground using sound quality as a differentiator?
Will tighter noise emission legislation impact your product sales? Would you like to decrease the amount of time spent on basics
such as predicting sound fields or shave off weeks on a more complex job like an engine run-up? In the past, parametric analysis
and design refinement was simply not feasible because of cost and time constraints - the only option was to apply expensive
techniques late in development stage at the expense of design flexibility. This is no longer the case.
Real time-saving opportunities
With the revolutionary breakthroughs embedded in the various
LMS Virtual.Lab Acoustics solutions, you can now remodel
design changes within minutes, perform acoustic meshing in • Gain full insight into acoustic
a couple of hours and predict an engine run-up within a day. problems
You’ll be able to make well-informed decisions during the
concept stage, and systematically refine and optimize your • Accurately and quickly predict
product’s acoustic performance from the initial design to design change effects
• Minimize the cost and weight
Faster than ever acoustic simulation of sound treatment
By integrating ground-breaking LMS SYSNOISE technologies • Reduce noise levels and
into LMS Virtual.Lab Acoustics, LMS has created the world’s incorporate desirable sound
first end-to-end environment for acoustic performance
engineering from concept development and design refinement
before prototype testing
using virtual models to test-based validation. LMS acoustic
solutions cover routine applications, such as structural noise
radiation and cavity field simulations, and address specific
acoustic engineering issues, like engine run-ups, flow-induced
noise or random acoustic loading.
4 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
LMS Virtual.Lab Acoustics Solutions for:
Automotive and Ground Transportation
LMS Virtual.Lab Acoustics provides everything that engineers need to model, analyze
and refine interior sound quality in passenger cars, trucks, busses, off-highway vehicles
and trains. Engineers can start solving complete engine and transmission acoustic
radiation problems from the design stage. Load identification based on experimental
techniques or multibody analyses provides the accuracy required for any operating
condition. Using LMS Virtual.Lab Acoustics, engineers can analyze orifice noise and
shell noise caused by mechanical and acoustic loadings of lightweight components,
like mufflers and intakes.
LMS Virtual.Lab Acoustics accurately predicts aircraft interior acoustics taking both
structural and airborne transmission paths into account. LMS Virtual.Lab Acoustics
helps aircraft engine manufacturers reducing engine noise to comply with ever
stringent government regulations and increase passenger comfort. Random acoustics
technologies make it possible to calculate fuselage structural behavior with a random
pressure field applied to its surface.
With stricter government noise regulations for large industrial machines, LMS
Virtual.Lab is increasingly used to simulate radiated acoustics caused by large
industrial engines, gearboxes, pumps, compressors, electric transformers and
other industrial products.
Consumer and business electronics
Consumer goods manufacturers use LMS Virtual.Lab Acoustics to minimize noise
levels on a variety of products ranging from refrigerators and dishwashers to washing
machines, microwave ovens and drills. Loudspeaker or mobile phone manufacturers
apply LMS Virtual.Lab Acoustics to optimize design sound quality. Typically a
combination of boundary element and finite element approaches are used to simulate
both internally and externally radiated acoustics.
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 5
Acoustic simulation: an integral
part of the engineering process
Re-use CAD and CAE models Complete the model
For an easy start into the acoustic engineering process, LMS Even for incompatible structural models, it is easy to create
Virtual.Lab Acoustics seamlessly links to key CAD, CAE and even structural vibration loads for acoustic calculations. You can quickly
test tools. No more time lost in recreating models, re-meshing for build in acoustic properties, such as frequency dependent absorbent
different applications, or endlessly converting between different surfaces, add complexity for detailed studies or automatically
file formats. Just use your preferred Finite Element (FE) solver for generate ISO field-point meshes. Acoustic source definitions
structural analysis and even run it in the background of the LMS range from simple point to sophisticated distributed sources such
Virtual.Lab environment. as random pressures and diffuse fields. For designs with moving
parts, you can perform a system-level mechanical simulation using
Create the acoustic mesh LMS Virtual.Lab Motion to accurately predict forces and resulting
structural vibrations for significantly more insight into the cause of
LMS Virtual.Lab Acoustics dramatically accelerates both cavity the acoustic problem.
and exterior acoustic meshing processes. For exterior meshing,
the approach can be compared to wrapping the structure with a Solve tough acoustic problems
rubber sheet: small surface features are smoothed while features
responsible for the acoustic response remain in place. Acoustic To reduce design calculation times, robustness and calculation
meshes are automatically validated; free edges and junctions speed are two critical attributes for successful acoustic simulation
are detected to ensure proper boundary conditions and potential in mainstream product development. This is why key elements of
problems are flagged to prevent errors rippling through the process. SYSNOISE, a core LMS technology, have been implemented into
LMS Virtual.Lab Acoustics.
Besides dedicated solvers in the frequency domain for stationary
problems and the time domain for transient calculations, there are
modal solvers, direct solvers, high-speed iterative FEM solvers,
high-speed BEM solvers, a fast multipole BEM solver, parallel solvers
and Acoustic Transfer Vector (ATV) solvers.
6 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
Visualize and interpret results
Engineers need to verify acoustic performance, identify existing acoustic problems and
develop qualitative solutions. They need a wide range of specialized post-processing tools to
manipulate, visualize and interpret data. LMS Virtual.Lab Acoustics has it all. From the initial
avalanche of results, you will be able to grasp the most significant information, post-process
it, identify design trends, and create graphical acoustic data representations. Stunning visual
animations help you to inspect structural vibration and acoustic patterns while providing
deeper insight into what is actually happening.
Reﬁne and optimize your design
Take full advantage of LMS Virtual.Lab Acoustics to swiftly predict the effect of any design
change. A very effective parametric analysis capability helps you to automate the process
workflow. For example, it enables you to apply new engine run-up excitation data to an existing
engine acoustic model and compare the previous results with the new results and target
values. By using Design Of Experiments (DOE) and optimization, you can automatically explore
the design space and balance parameters for optimal and reliable acoustic performance
against non-acoustic constraints like weight or durability.
Automation and scripting
LMS Virtual.Lab Desktop offers the possibility to record and playback repetitive processes,
such as load assignment, source assignment or an engine radiated acoustic simulation
set-up. With Visual Basic scripting, you can further customize tasks, performing a standard
computation with one-click of a button or generating and distributing a report.
LMS Virtual.Lab LMS Virtual.Lab Acoustics
Mesh based Structural Vibration Acoustic Acoustic
Pre-processing Loads Simulation Simulation response
Start the analysis from CAD Easily transform the structural mesh Apply the test-based or simulation- Compute the acoustic radiation
models directly imported in the into an acoustic mesh. Meshing based excitation data on the and visualize the pressure at field
LMS Virtual.Lab environment. is automatically adapted to the motor and compute the acoustic points. Create easy to interpret
desired frequency of the analysis. potentials. color map of the radiated power.
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 7
LMS Virtual.Lab Acoustics Pre/Post VL-HEV.21.1
The LMS Virtual.Lab Acoustics Pre/Post embeds a full set of pre- and post-
processing capabilities for acoustic simulation. It creates a complete acoustic
model with the LMS Virtual.Lab Acoustics solvers and enables the user to
post-process the model through standard and advanced displays.
In pre-processing mode, one can select the model options: Direct, Indirect BEM or
Acoustic FEM; define the acoustic geometry, check the mesh quality and correct
where needed. Acoustic properties such as absorbent panels, boundary conditions
including vibrating boundary conditions and sources can be defined. Field point grids
for results output (microphone locations) can also be generated on various standard
shapes (sphere, hemisphere, box, plane…) or by importing from external files.
As for acoustics analysis, one can work through different meshes (e.g. imported from
external files). It is possible to verify and solve conflicts inside the model, for example Colorbar plotting for acoustics, easily highlighting
node, element or property number conflicts can be addressed. Basic acoustic mesh critical locations.
creation tools are included as well. For example, the skin creation converts a solid
structural FEM mesh into a surface acoustic BEM mesh for acoustic analyses.
In post-processing mode, one can deeply examine the results of an acoustic analysis.
Standard displays such as 2D displays for sound power (including dB weighting) are
supported and provide a basic understanding of the noise issues. These standard
displays are complemented by advanced displays such as waterfall and colormap
displays for the acoustic radiation of rotating machinery or a given path. Modal
and panel contribution displays highlight the most critical radiating parts of a
system providing much more insight. In addition to the function displays, a variety
of 3D results displays is supported including standard SPL images up to advanced
sound directivity and 3D contribution result images. These can be viewed for one
specific critical frequency or scrolled through the frequency band of interest.
Field point mesh (equivalent to microphone positions)
around the radiating gearbox.
• Acoustic pre-processing: full range of • Efficient acoustic pre-processing through
Boundary Conditions including different dedicated libraries of acoustic features
types of acoustics sources and surface • Capability to deal with a large variety Waterfall diagrams showing noise levels in run-up
vibrations for BEM and FEM solutions of acoustic problems through the conditions.
• Acoustic pre-processing: definition availability of dedicated features
of acoustic properties including fluid for specific acoustic problems
properties, constant or frequency • View the acoustic results and efficiently
dependent impedances, transfer pinpoint critical areas of a structure
impedances and absorbent materials through advanced analysis capabilities
• Acoustic post-processing: wide set of
function displays and 3D images including
complex function displays, 2.5D waterfall
and colorbar displays, contribution
displays and 3D results viewing of
pressures, velocities and sound power
Dedicated 2D plotting for noise and vibration analysis.
8 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
LMS Virtual.Lab VL-VAM.35.2
Boundary Element Acoustics
LMS Virtual.Lab Boundary Element Acoustics is an entry-level, easy-to-use acoustic
simulation tool to predict and improve the sound and noise performance of a broad
range of systems. With straightforward models and embedded solver technology,
engineers can acquire results faster without compromising accuracy.
LMS Virtual.Lab Boundary Element Acoustics uses the boundary element method
(BEM), which effectively reduces complex 3D geometry to 2D surface dimensions.
Only the surface areas of the structural systems that are vibrating or scattering sound
need to be modeled. BEM model sizes are typically limited to a few thousand elements,
resulting in relatively small, easy-to-create, check and handle models compared to
complex 3D finite element models. These reduced models deliver results in a shorter
timeframe, helping users to quickly evaluate the acoustic design performance. Noise radiation from an automotive intake system.
LMS Virtual.Lab Boundary Element Acoustics can accurately model structural-
acoustical coupling phenomena, common in lightweight structures when acoustic
sources make the structure vibrate. For example, strong variations in engine pressure
will make the engine intake vibrate, generating additional radiated noise.
This solution tackles both internal and external radiation problems and covers a
broad range of applications, such as transmission loss through panels, electronic or
household equipment sound quality and radiated noise. The solution runs transparently
with other CAE codes and includes seamless links to Abaqus, Ansys, CATIA CAE,
I-DEAS, Nastran, and Permas. It is an ideal starting point for advanced and specialized
Minimize the noise radiation from oil pans.
• Indirect and direct boundary • Find the cause of noise problems
element methods quickly with minimal modeling effort
• Full vibro-acoustic coupling • Predict acoustic performance Sound directivity patterns from loudspeakers.
• Plotting and 3D imaging: SPL, accurately and minimize design risk
ISO 3744 Sound Power, RMS, dB • Mesh coarsening and high-speed BEM
weighting, (1/3) octave, TL options accelerate the process even more
• Surface absorbing panels
• Boundary conditions: surface vibrations
and pressures, acoustic sources
Wind turbine radiating noise into the environment.
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 9
LMS Virtual.Lab Fast Multipole Boundary VL-VAM.41.2
Multipole BEM (Boundary Element Method) is a boundary element technique that
• Indirect Boundary Element Method
specifically addresses ultra-large BEM problems. This new technique complements • 1-way coupling taken into account
existing BEM techniques: a classical BEM solver can address BEM models up to 20 • Acoustic sources, vibrating
000 nodes efficiently, where the advanced LMS Virtual.Lab Fast Multipole Boundary boundary conditions and impedance
Element solver can handle models up to one million nodes and more. In this way, larger boundary conditions
problems regarding higher frequencies can be tackled, which makes the BEM method • Iterative solver with multipole expansion
very scalable. and performant pre-conditioner
• Fully scalable on parallel systems
The fast Multipole BEM module implements high-speed iterative techniques to solve
the BEM equations, with additional sophisticated algorithms based on multipole
expansion and multi-level hierarchical cell substructuring. Instead of solving the model
in one go, the module automatically splits up the model in domains, which in turn are
split up again and again. Each small domain is treated as a classical BEM model. A
translator operator describes the relation between the domains and the fast iterative
algorithm solves the complete model. The total computation time is quasi linear to the
number of nodes of the BEM model, which requires less memory. The model is run on
Windows PCs, multi-CPU systems and clusters.
With this technique, running models becomes faster and a complete new set of Benefits
applications can be addressed, such as the study of exterior acoustics of complete • Solves ultra-large BEM problems: up
vehicles up to several 1000Hz, aircrafts, ships, submarines, large engines including to 1 million elements and more
enclosures, turbines and more. • Computes large BEM models much faster
• Reduces acoustic pre-processing time
• Allows to increase the frequency
range of analysis drastically
A large size 8000 Hz Acoustics model can be solved Noise radiated from a HD recorder at 10kHz using a
efficiently using Fast Multipole BEM huge BEM model composed of 100 000 nodes.
Ultra-large BEM model of 2 cars passing. Pass-by-noise simulation of a full vehicle up to
10 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
LMS Virtual.Lab Finite Element Acoustics VL-VAM.36.2
Compared to the boundary element method, LMS Virtual.Lab Finite Element Acoustics Features
offers a more advanced method for simulating acoustics. Like the boundary element
• Infinite finite element method
method, it helps predict and improve the sound and noise performance of a broad • Full vibro-acoustic coupling
range of systems. The main difference between the boundary element method and the • Plotting and 3D imaging: SPL,
finite element method is that for the latter you need to model the propagation area, ISO 3744 Sound Power, RMS, dB
that being air or water. weighting, (1/3) octave, TL
• Iterative Krylov solver, parallelization, ATV
Finite element includes other advanced techniques, such as an infinite finite element FEM to achieve optimum solver speeds
method that helps the user to surround a reduced finite mesh so a radiated acoustic • Temperature fields, volume absorbers,
simulation can be performed without having to model the entire propagation area. flow effects (turbines, mufflers)
LMS Virtual.Lab Finite Element Acoustics can be used to perform acoustic simulations
in both time and frequency domains. A time domain simulation example would be the
noise made when a car door slams. Other finite element examples are temperature
fields and flow effects in turbines or volume absorbers in mufflers.
Like the boundary element method, the Finite Element Method (FEM) can simulate a
fully coupled vibro-acoustic simulation to determine how acoustic sources affect the
Advanced finite element solvers are also available, like the Krylov solver that increases • Account for multiple material properties
computation speed by 100 times and archives the acoustic transfer vectors to perform • Fast calculation times: computation gains
multiple runs in a matter of minutes. Combined with the ability to perform parallel up to 100 times faster with the Krylov solver
simulations, this increases simulation times up to 16 times using multiple processors. • Find the cause of noise problems
quickly accounting for temperature
fields, flow effects, …
• Predict acoustic performance
accurately and minimize design risk
• Volume mesh generate options to
quickly produce complex FEM meshes
Maximize tranmission loss of a muffler part of a Model the attenuation of an exhaust system.
Model acoustic radiation inside truck cabin. Noise radiation of a tire using infinite elements.
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 11
LMS Virtual.Lab VL-VAM.38.2
Numerical Engine Acoustics
LMS Virtual.Lab Numerical Engine Acoustics is an efficient tool to predict noise • Boundary element method
radiated throughout a full engine run-up and gain insight into noise problem causes in • Create acoustic BEM mesh
general. With this comprehensive solution, engineers can simulate and optimize the based on structural mesh
engine design for top acoustic performances. • ATV-based calculation
(acoustic transfer vector)
LMS Virtual.Lab Numerical Engine Acoustics uses excitation forces obtained from • Integrated structural forced
dynamic multibody analyses (LMS Virtual.Lab Motion), one dimensional calculation
• Structural excitation from measurement,
tools (LMS Imagine.Lab AMESim) or from measurements. Dynamic load data and multibody simulation, multi-load case
structural modes, calculated by using standard FE codes, are used to determine (multi-rpm) and order analysis
surface vibrations from which acoustic radiation is predicted. • Acoustic pressure & structural
With LMS Virtual.Lab Numerical Engine Acoustics, engineers can create acoustic • Plotting and 3D imaging: SPL,
meshes very quickly. The BEM (boundary element method) acoustic mesh ISO 3744 Sound Power, RMS,
automatically adapts to the analysis frequency. As a result, an accurate acoustic mesh dB weighting, (1/3) Octave
can be generated in hours instead of weeks.
This solution’s solver uses unique and efficient ATV (acoustic transfer vector)
technology to perform very fast multiple rpm runs and accelerate calculation reruns
when analyzing alternative designs. Based on surface vibrations, total radiated noise Benefits
and sound pressure levels in predefined locations are predicted, which reduces the • Predict radiated noise in time
total engine noise radiation process from months to a day. for every design loop
• Verify noise levels according to
Based on the results, engineers can analyze the total radiated power through ISO specifications, find possible noise causes
3744 meshes and even acoustic sensitivities with regard to excitation forces. They can and suggest design improvements in time
• Gain more insight into acoustics problem
access a comprehensive set of clear visualization tools to investigate obtained sound
& facilitate design improvements
Structural finite element model of an engine. Modal deformations of an engine.
The acoustic model contains a reflecting ground plane Results showing noise radiation patterns and total
and the microphone positions (typically ISO3744). radiated noise in run-up conditions.
12 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
LMS Virtual.Lab Acoustic Fatigue VL-VAM.39.2
System noise and vibration characteristics can be random by nature. To accurately
address noise and vibration issues, engineers must address these problems from a Features
randomly statistical point-of-view. High acoustical excitations induced by a powerful • Vibro-acoustic simulation using
jet or rocket flow are naturally random and induce random vibrations in the aircraft random loading input
fuselage, spacecraft launcher fairing panels or satellite. These vibrations cannot actually • Obtain acceleration data at
be determined, but are rather interpreted as power spectral densities or PSDs. In this any structural point
case, potential induced fatigue damage is random by nature and directly linked to the • Perform stress recovery in
PSDs of the resulting stress.
LMS Virtual.Lab Acoustic Fatigue is a dedicated solution that addresses random
acoustic fatigue problems. By integrating Random Vibro-acoustics and Random Fatigue
modules, this solution helps engineers understand the random vibro-acoustic behavior
of a given structure and predict fatigue hotspots and corresponding fatigue life to
optimize design for fatigue performance.
LMS Virtual.Lab Acoustic Fatigue handles both structural and acoustic responses
using vibro-acoustic results for durability analysis. Working with acoustic responses,
the solution supports transmitted and scattered sound due to random structural and/
or acoustical excitations. For structural responses, this solution can calculate vibration
amplitudes, as well as support stress recovery by providing stress spectral densities
for structural elements based on stress modal vectors obtained by standard FE solvers.
From this, engineers can assess critical structural points in terms of vibrations and • Use BEM technology to perform a fully
stress levels and use these for fatigue life predictions. coupled vibro-acoustics simulation
loading the satellite component
In addition, a mesh coarsening option provides powerful meshing tools that help to build with random pressure data
• Pinpoint critical hotspots using
high quality acoustic meshes extremely quickly, saving weeks of modeling time.
random loading accelerations
• Predict fatigue hotspots and fatigue
life using random loading from
Acoustic plane waves are impinging upon the Satellite vibrations due to noise hitting the structure.
structure, causing the satellite to vibrate.
Contribution plots highlighting cricital modes. Plot of the fatigue damage of the structure due to the
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 13
LMS Virtual.Lab VL-VAM.40.2
Advanced Interior Acoustics
Complementing the acoustic capabilities found in LMS Virtual.Lab Desktop, LMS
Virtual.Lab Advanced Interior Acoustics is an end-to-end process solution for
interior noise analysis. Its single user environment integrates all the necessary
process components: vibro-acoustics modeling, excitation and boundary
conditions set-up, fluid-structure coupling analysis with an optional Nastran
run, and excellent visualization, interpretation and refinement possibilities.
LMS Virtual.Lab Advanced Interior Acoustics is a premium solution using Virtual.Lab
Acoustics solvers. Dedicated tools include a cavity mesher that quickly generates an
acoustic finite element mesh of the interior. The result is a high-quality, frequency-
dependent HEXA-element mesh, which accounts for smooth and sharp features.
Acoustic modes of the interior of a vehicle.
The acoustic solver offers a complete set of frequency-dependent acoustic properties,
such as panel absorption or volumetric absorption from vehicle seats. Structural
damping from the trim can also be modeled and optimized for better interior acoustics.
Cavity acoustic modes can be solved efficiently using fast iterative solvers and deeply
analyzed for an initial insight into interior acoustic issues. A unique ATV technology
that reuses acoustic Finite Element Method (FEM) solutions from a first run can be
used to quickly model different design variants with multiple loading conditions.
LMS Virtual.Lab Advanced Interior Acoustics features panel contribution analysis
capabilities to help assess individual panel contribution to the overall internal vehicle
sound pressure. Detailed grid contribution or hot spot detection is also supported to
thoroughly understand and pinpoint problems. Optionally, LMS Virtual.Lab Advanced
Interior Acoustics can be extended with Path and Modal Contribution Analysis to
identify system structural modes that contribute most to interior noise level and can
identify which path is predominantly involved in sound transmission into the cabin.
Panels from which noise is radiated into the interior.
• Finite element and ATV-based methods • Fast and automatic creation of
• Modal analysis for both fluid and structure acoustic finite element meshes
• Automatic cavity meshing • Data transfer and mapping from Increase the fidelity of the interior acoustic simulation
from structural model structural to acoustic mesh by including the relevant components, such as seats
• Panel definition based on element • Multiple fluid/structure interaction options and dash panels.
face groups of structural and/or • Easy and flexible panel set-up for
acoustic meshes independent of FE contribution analysis, defining
property or material definitions sets on element faces for the
• Nastran driving for all relevant structural or acoustic mesh
Nastran solution sequences (SOL • Automatic Nastran driving tailored for
103, 107, 108, 110, 111) NVH and interior acoustics usage
• Dedicated post-processing for • Easy result post-processing with a wide
visualizing panel contributions range of flexible contribution displays
• Create a cavity mesh and mapping
between the structure and cavity
mesh with the automatic cavity
mesher and multiple structural-
acoustic coupling definition options
Structural deformation patterns at critical frequencies
highlight potential critical areas.
14 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
Aero-Acoustic Modeling VL-ACM.41.3
After significantly reducing primary noise sources, such as road or automotive
engine noise or structural hydraulic noise, engineers today are faced with the
complex task of reducing all types of flow-induced noise found in various markets.
Aero-Acoustic Modeling coupled with the BEM (Boundary Element Method)
technology helps engineers to accurately predict and solve aero-acoustic noise
problems, ranging from fan noise in electrical appliances and wind turbines to
turbulence-based noise in aircrafts.
Aero-Acoustic Modeling uses a pragmatic approach to predict aero-acoustic noise,
based on aero-acoustic analogies. It derives equivalent aero-acoustic sources from
flow equations calculated with any Computational Fluid Dynamics (CFD) vendor,
supporting the CFD General Notation System (CGNS) interface. It then calculates Noise radiated from a fan blower, through a duct into
the resulting radiated or scattered noise using BEM technology. free field.
This efficient and cost-effective solution only requires system boundary modeling,
resulting in relatively small acoustic models that are easy to create and check, yet
provide accurate solutions to real-life problems. Powerful post-processing tools
enable engineers to analyze and visualize results for acoustic refinement.
Noise radiated from a mirror, propagated to the car
Fast Trim VL-ACM.31.3
The Fast Trim module helps users to evaluate the acoustic performance of multiple
layers, like carpet, wood, or foam for absorption and transmission. Multiple
layers are applied to a base structure. Results are given as complex frequency-
dependent transfer admittances, which convey the local relationship between
pressure and velocity on both multi-layer sides: the cavity side and the base
structure side. Results are used to assess the influence of multi-layered materials
on the global acoustic system performance in, for example, vehicle and airplane
Firewall carpets, floor carpets, roofliners constitute
complex vibro-acoustic systems.
Multi-layer trim properties applied on the various
panels inside the car.
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 15
LMS Virtual.Lab Acoustics – Options
The Virtual.Lab Motion Suspension provides a dedicated, easy-to-use interface to
LMSATV BEM & FEM solver sets up and launches an acoustic BEM or FEM modelto model
compute suspension. The interface vectors (ATV). through the database is used of
a vehicle and store acoustic transferguides the userThe resulting complete process in a
suspension modelling nal response sequence, either seamlesslythe hard point locations,
standard ATV-based fi and analysis, starting from the import of from the ATV computation
or at a later time. The vibration response simulation results are then combined with
then via components and connections definition up to dedicated post-processing an
ATV set to efficiently calculate simulations. Additionally, the user can choose to 100-fold
capabilities from virtual test rigthe noise radiated from a vibrating surface. Up to astart from
speed increases can be obtained compared to model allowing to significantly increase
a pre-defined suspension template as an initial conventional acoustic simulation methods.
productivity. tool, a machinery noise signature can be simulated within a day rather than
Using the ATV
weeks and results can be post-processed using the LMS Virtual.Lab Acoustics graphical
High Speed BEM
The High Speed Motion Vehicle Modeling provides chassisthreesuspension analysts a
LMS Virtual.Lab BEM Solver module starts by computing and to four master frequencies.
dedicated and easy-to-use results for model vehicles for any kind of performance study:
From this point, it predictsinterface toall the remaining frequencies using an intelligent
mathematical process based on Padé expansion. noise and durability. It allows a modular
handling and steering handling, ride comfort, road Although solving each master frequency
is more time-consuming compared to conventional BEM, computations at slave
assembly of the vehicle from separate subsystems (suspensions, steering system, braking
frequencies are dramatically faster. Overall,up and post-process a number of standard
system, driveline) and it allows to easily set this module speeds up acoustic radiation
calculations by up to a factor of 30.
vehicle manoeuvres (ISO and others). A basic driver model (for path following) is included
as well allowing closed-loop maneuvers.
For modelling braking, steering and driveline systems, dedicated modules are offered to the
IPG-DRIVER for LMS Virtual.Lab
Acoustic Parallel Processing (stackable 4-node)
The IPG-DRIVER for LMS Virtual.Lab Motion adds the actions of the human multi-CPUs
This solver helps the acoustic solution to occur on multiple nodes, such as driver to the
or multiple vehicle simulations. As As an allows simulating closed-loop quickly, this
multi-body computers in a network.such, itideal way to solve large modelsmanoeuvres for
vehicle dynamics performance testsconfigurations including frequency level, matrix level,
solution is applicable to a variety of in the most realistic circumstances. The IPG-DRIVER
is seamlessly integrated in LMS Virtual.Lab Motion and is the industry standard driver
thread level or a combination.
model, based on more than 15 years of development by IPG Automotive in Karlsruhe,
Germany. Based on the desired path, the desired speed and the chosen driver style
(from defensive to racing), the IPG-DRIVER calculates the pedal positions (gas, brake and
clutch), the gear shifter position and the steering wheel input.
Tracked Vehicle Modeling
Using the Modifi Motion Tracked Vehicle provides a convenient interface modified
LMS Virtual.Lab cation Prediction module, users can very quickly analyzeto simplify
designs and simulate acoustic behavior for a track. The track can be either a a limited
the process of modeling a complex mulit-partlarge number of design options inrubber/
time. The module applies of design metal links. The interface collects concise
elastomeric belt, or madethediscretemodification on the structural modes and assesses
the influence of structural ne the track geometry, mass properties, stiffness resolving the
information needed to defichanges on the overall noise performance withoutand
damping. structural or acoustic equations. with appropriate stiffness, damping, and
complete Multiple bodies are then created
initial conditions. All the needed contact force features are also automatically created.
Customers who want to learn about the complex dynamic behavior of a track system
interacting with the ground and the vehicle will find this a powerful and useful tool.
Random Vibro-Acoustic analysis
Using advanced Motion value decomposition studying dynamic performance of cable-
LMS Virtual.Lab singularCable Modeling allowstechniques, this module accounts for
pulleys systems and quantifying loads on pulley bearings and cable guides. The dedicated
the random nature of certain noise and vibration characteristics typically found in the
aeronautics and aerospace industry. quickly define the pulleys, guides, cable path and
Cable Modeling Tool enables users toThis includes high acoustical random excitations
cable properties and then automatically build vibrations cable model including stiffness,
induced by jets or rockets that cause random a discrete of the fairing and spacecraft itself.
friction, contact … Engineers can efficiently explore design changes to cable and pulley
properties on their parameterized LMS Virtual.Lab Motion model. The Cable Modeling Tool
provides modeling scalability: the cable axial tension properties can be extended with
bending and twist properties depending on the effects that need to be studied.
16 LMS Virtual.Lab Acoustics LMS International | email@example.com | www.lmsintl.com
Road Proﬁle Interface
Traditionally, fatigue damage is associated with way to make a complex 3D road profi
The Road Profile Interface provides a convenient time-dependent loading; however, le
there are often situations in which loading time for the cannot easily be determined,
or surface. The new feature generates geometry signals road surface from 3 different file
sources.wind load on a wind turbine. In this case, random vibration fatigue powerroad
like the Spline curves, spline surfaces, and the CDTire ROAD 2000 format. The
surface feature is aimed at connecting other cases, loads are deterministic, but defined
spectral densities define the loads. In the analytical road surface used by the solver with
the visualized For efficiency reasons, it is desirable to perform the complete simulation
in frequency. geometry.
in the frequency domain. With Vibration Fatigue, LMS integrates its cutting-edge
knowledge in durability assessment methods. Users can benefit from an easy and
consistent set-up and highly efficient analysis methods, including real multi-axial load
and local stress behavior as well as the seam and spot welds.
This innovative mesh coarsening to model for forces acting between rotating wheels
The Standard Tire provides a waytechnique tire exterior meshing can be compared to and
wrapping Three forces with a rubber sheet: and vertical) features resulting moments
the road. the structure (lateral, longitudinal, small surfaceand threeare smoothed to are
calculated based on the modelrelationship selected, that have a significant impact on the
dramatically reduce the force size. Model features and then applied to the wheel part in
acoustic response remain in place to preserve the quality and accuracy of the
the model. There can be several tire force relationships included in a model. acoustic
simulation. A simple user interface requests the obtainable frequency range from the
Nonlinear stiffness and damping, distributed contact, and advanced traction effects are
structural mesh and then performs the necessary wrapping. Using this meshing approach,
included. In addition, users can edit the tire force source code and make changes to
users can create complex acoustic models in hours.
include special force features.
Standard Tire includes the international standard called “STI” – the Standard Tire
Interface, to link external tire models to LMS Virtual.Lab Motion.
TNO MF-Tire for LMS Virtual.Lab
TNO’s MF-Tyre tyre models enable accurate full vehicle ride & handling, comfort and
The cavity meshing tool helps users to generate a high-quality HEXA-dominant mesh
durability analysis in LMS Virtual.Lab Motion.
directly from the structural model, ensuring close proximity between the two. A
mechanism models can and repairing holes and thus defining the cavity aircraft
The MF-Tyrefor detectingbe used for passenger car, motorcycle, truck andis employed
landingagear dynamicmesh is created automatically. The required automation level can
before high-quality simulation.
be determined by the user that allows either the entire vehicle cavity or just specific
MF-Tyre to be meshed. The meshing algorithm can competently handle sharp and
MF-Tyre features, seatsimplementationusing the adaptive mesh feature.
smooth is Delft-Tyre’s and footprints (revision 6.0) of the world standard Pacejka Magic
Formula tyre model.
MF-Tyre’s semi-emperical approach based on laboratory and road measurements
enables fast and robust tyre-road contact force and moment simulation for steady-state
TNO MF-Swift for LMS Virtual.Lab
The CFD General Notation System (CGNS) provides a general & handling, comfort and
TNO’s MF-Swift tyre models enable accurate full vehicle ride standard interface, which
durability analysis in LMS Virtual.Labdynamics (CFD) analysis data into LMS Virtual.Lab.
is used to import computational fluid Motion.
This makes it possible to interface used for passenger that support the CGNS export
The MF-SWIFT tyre models can bewith all CFD vendors car, motorcycle, truck and aircraft
landing gear dynamic simulation. an input source for aero-acoustic simulations.
functionality. This data is used as
MF-Swift is the high frequency extension to the Magic Formula MF-Tyre model. MF-Swift
adds generic 3D obstacle enveloping and tyre belt dynamics to MF-Tyre’s tyre-road
contact force and moment simulation.
MF-Swift has been developed and extensively validated using many measurements.
Virtual.Lab Optimization provides a allows engineers to do full for single and
LMS CDTire (Comfort and Durability Tire)set of powerful capabilities vehicle ride comfort
multi-attribute optimization. Through design of experiments account tire belt dynamics
and durability analysis in LMS Virtual.Lab Motion taking into (DOE) and response surface
modeling (RSM) techniques, surfaces.
and interaction with 3D road engineers gain rapid insight into all possible design options
that CDTire can c used for passenger advanced optimization routines including Six
LMS meet specifiberequirements. Using car and truck simulation.
Sigma the multi-body LMS Virtual.Lab automatically selects the optimal design, taking
During manufacturing, simulation LMS CDTire computes the spindle forces and moments
into account real-world the model while driving the 3D road surface. LMS CDTire
acting on each wheel in variability while meetingon a strictest robustness, reliability and
accurately captures the vibrations in the frequency range for durability and comfort
studies. Belt vibrations are simulated up to 80 Hz.
LMS CDTire : 3 scalable tire models
LMS International | firstname.lastname@example.org | www.lmsintl.com LMS Virtual.Lab Acoustics 17
LMS is an engineering innovation partner for
companies in the automotive, aerospace and
other advanced manufacturing industries. With
approximately 30 years of experience, LMS helps
customers get better products to market faster and
turn superior process efficiency into key competitive
With a unique combination of 1D and 3D simulation
software, testing systems and engineering services,
LMS tunes into mission critical engineering
attributes, ranging from system dynamics, structural
integrity and sound quality to durability, safety and
power consumption. With multi-domain solutions for
thermal, fluid dynamics, electrical and mechanical
system behavior, LMS can address the complex
engineering challenges associated with intelligent
Thanks to our technology and dedicated people,
LMS has become the partner of choice of more than
5,000 leading manufacturing companies worldwide.
LMS INTERNATIONAL LMS is certified to ISO9001:2000 quality standards
Researchpark Z1, Interleuvenlaan 68 and operates through a network of subsidiaries and
B-3001 Leuven [Belgium] representatives in key locations around the world. For
T +32 16 384 200 | F +32 16 384 350 more information on LMS, visit www.lmsintl.com.
email@example.com | www.lmsintl.com
Worldwide For the address of your local representative,
please visit www.lmsintl.com/lmsworldwide