LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Noise and Vibration From component to system-level noise and vibration prediction 2 LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Noise and Vibration 3

LMS Virtual.Lab Noise and Vibration From component to system-level noise and vibration prediction While it is relatively easy to predict performance at the component level, most noise and vibration issues are only discovered at the full system level. Experience shows that making extensive prediction models is a tedious and difficult process, one that does not necessarily produce results that match reality. How can you quickly and reliably synthesize system-level models? How can you accurately predict the most critical noise and vibration contributors and identify the best design modifications? The total process approach to noise and vibration engineering A vehicle s NVH performance largely depends on the various loads the vehicle carries and the resulting complex interactions between numerous components and connections. This is why noise and vibration engineering optimizes the vehicle as a singular, complete system. From the concept development stage onwards, LMS Virtual.Lab Noise and Vibration supports vibro-acoustic assessment on full-system models, capturing all critical process steps to systematically improve noise and vibration characteristics throughout the total system. Delivering the right noise and vibration performance Enriched noise and vibration analysis with data from various engineering domains LMS Virtual.Lab Noise and Vibration offers a unique hybrid simulation approach that intelligently combines Finite Element (FE) modeling with test-derived models. Besides the link to testing, LMS Virtual.Lab Noise and Vibration can also use simulated data from multibody and flexible body simulations created in LMS Virtual.Lab Motion. In this way, users can define realistic load cases according to actual model dimensions to determine the optimal time-domain performance. LMS Virtual. Lab Noise and Vibration can be used to generate data for more in-depth acoustic analysis using LMS Virtual.Lab Acoustics. LMS Virtual.Lab Noise and Vibration allows engineering teams to evaluate the vibro-acoustic behavior of multiple vehicle-variants. Its industry-standard solvers execute fast and accurate predictions while dedicated post-processing capabilities provide immediate feedback regarding vibroacoustic responses and transfer paths. 4 LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Noise and Vibration Solutions for: Automotive and Ground Transportation LMS Virtual.Lab Noise and Vibration provides tools to analyze and improve the noise and vibration performance of entire roadworthy vehicles or separate components. Both engine and road noise can be incorporated into the design picture by using deterministic order loads and random road excitation data. Dedicated post-processing tools help users to explore various modal or path contributions to a certain response. Users can also define how different sub-systems, like the engine or suspension system, interact with each other and the vehicle body. Aerospace Different rules apply to the aerospace industry. A safe satellite launch depends on the dynamics of the entire satellite-launcher system. With LMS Virtual.Lab Noise and Vibration users can optimize the satellite vibration performance together with the fully equipped launcher to guarantee the integrity of expensive equipment during launch. Besides system dynamics, launching conditions can be simulated using cross spectral densities as excitation data to determine if structural changes are required. Industrial machinery Noise and vibration impacts the industrial sector in a variety of ways. Machine operators are continuously exposed to various noise and vibration levels and government regulations are in place to protect the health and safety of people on the production floor. In other situations, vibration levels interfere with product quality. LMS Virtual.Lab Noise and Vibration helps users to understand where vibrations start and how they can be improved. Integrate test-derived component information in full-system simulation models Analyze critical noise and vibration contributors and identify optimal design modifications Refine noise and vibration performance before building the first prototype Reuse data from other LMS Virtual.Lab modules to meet targets and design restraints LMS Virtual.Lab Noise and Vibration 5

An effective process to optimize design prior to physical prototyping LMS Virtual.Lab Noise and Vibration provides all the tools to create system-level NVH models based on subsystems and components. Throughout the development, modifications to individual FE or testderived components and assembly connections can be inserted to improve the system-level NVH performance. With its unique capability to incorporate both test-based and FE-based models in an assembly, the LMS Virtual.Lab Noise and Vibration hybrid solution offers its users both the accuracy and design flexibility they need to produce reliable simulation results. Fast iterations provide maximum insight into the system- or componentlevel NVH behavior, to steer the development from the initial stage onwards. Assembly of a multitude of test and FE components. Building realistic load cases Loads that reliably represent realistic customer usage are a key prerequisite for accurate noise and vibration prediction. LMS Virtual.Lab Noise and Vibration offers maximum flexibility when it comes to load case retrieval and respective system assembly placement. It handles any type of dynamic load data whether retrieved from force transducers or calculated from displacements or responses. Self-explanatory and easily interpretable results LMS Virtual.Lab Noise and Vibration offers a wide range of visualization and analysis tools dedicated to noise and vibration engineering. These post-processing options help users to efficiently investigate transfer paths and assess the noise and vibration contribution of individual vehicle or system parts. System-level modes and transfer functions. Efficient engineering refinement LMS Virtual.Lab Noise and Vibration is specifically developed to refine and optimize a design s vibro-acoustic behavior. Convenient tools help engineers to assess design-variant performance in a couple of minutes, quickly explore multiple options and use optimization routines to find the best possible solution. Response and contribution analysis. 6 LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab NVH Response Analysis VL-HEV.21.1 LMS Virtual.Lab NVH Response Analysis is an easy-to-use, entry-level simulation tool for predicting the noise and vibration behavior of a component, sub-system or complete model under operational loading conditions. With transparent access to all available models and load data from CAE and testing, users can integrate the best available data mix at all times. Fast modal and FRF-based prediction solvers quickly analyze a multitude of design variants. NVH specific post-processing tools help the engineering team compare actual responses with pre-defined or imported targets and optimize noise and vibration behavior. LMS Virtual.Lab NVH Response Analysis offers maximum flexibility when retrieving and applying load cases. The system accepts a multitude of load formats and types, derived from measurements, multibody or acoustic simulations, or generic loading sources. This includes structural forces, displacement excitations, and acoustic loads. The latter can be derived from structural vibrations on panels using acoustic source quantification. Combining measured loads with virtual models results in a more realistic NVH simulation as well as better and more reliable design insights. Transfer functions and modal contributions to transfer functions. Excitation and response degree of freedom displayed on the model. Engineers can easily set up NVH analysis runs with the template-based user interface, either starting from an FE model or using a test-based model. The solution also includes FRF and modal-based NVH response solvers to compute system noise and vibration responses. This results in fast simulation runs to process numerous design options in a limited timeframe. A wide variety of advanced post-processing tools help engineers investigate noise and vibration contributions of individual or grouped paths or modes to the final response and compare the response results with target data. LMS Virtual.Lab NVH Response Analysis supports techniques to execute design modifications from manually triggered modification analyses to fully automated design space explorations in combination with LMS Virtual.Lab Optimization. Forced response results displayed as model deformation and path contributions for fast problem assessment. Features Universal access to test and FE data for both model and excitation data Numerous supported load data formats: frequency, rpm or time-dependent data for force, displacement, velocity, acceleration, volume velocity and volume acceleration Fast modal and FRF-based forced response solvers Modal-based FRF synthesis to determine transfer functions from modal data Path and modal contribution analysis to determine the root cause of noise & vibration problems Wide variety of 2D, 2.5D and 3D displays to analyze operational responses Benefits Transparent access to the best available test & CAE data at any time Create templates that capture your analysis process and facilitate future calculations Make predictions more quickly with embedded FRF and modalbased NVH response solvers Increase response prediction accuracy using hybrid simulation: use measured loads with CAE or Test models Better result visualization with various intelligent NVH post-processing indicators and interactive visuals More insight into structural and acoustical contributions, path and modal contributions Modal results and synthesized FRFs. FRF-based forced response analysis on test-based body model. LMS Virtual.Lab Noise and Vibration 7

LMS Virtual.Lab System-Level NVH VL-NVC.35.2 LMS Virtual.Lab System-Level NVH is a comprehensive solution offering a wide range of tools to assemble components into hybrid system-level models and analyze noise and vibration performance under operating conditions. Engineers can easily build a model from one or more components, including FE components, test-based components or even CAD components. Components are connected by point connections with specific connection properties ranging from rigid connections to any particular frequency dependent complex stiffness. As the development proceeds and more detailed component models become available, different model parts can be gradually refined with more detailed FE or test-based component information. Once the simulation model is built, LMS Virtual.Lab System-Level NVH calculates the assembly s global dynamics using internal FRF-based or modal-based assembly solvers. The resulting assembled model consists of a set of transfer functions or modes that guarantee maximum accuracy and optimal speed for full-system noise and vibration assessment. Suspension component FE model. To predict noise and vibration behavior under operating conditions, the assembled models are combined with input loads from measurements, multibody simulations, acoustic simulation or generic sources. The solution computes noise and vibration responses using the internal modal or FRFbased forced response solvers or, optionally, an external FE solver. A wide range of NVH visualization and analysis tools help engineers to quickly investigate transfer paths and efficiently assess the noise and vibration contribution of individual system parts. Assembled hybrid vehicle model. Features Template-based node-to-node assembly of components with any connector type: rigid, spring-damper or frequency-dependent Tools to reposition and rescale components defined in different axis and unit systems Fast modal and FRF-based assembly solvers to determine system level dynamics Fast forced response solvers to determine the response of the system to operational loading Path and modal contribution analysis tools for efficient root cause analysis Benefits Easy model building, using test and FE components Assembly templates effortlessly replace and automatically reconnect component models FRF-based and modal-based NVH system synthesis and response solvers for efficient what-if analyses FRF-based system synthesis predicts to the mid-frequency range Measured loads combined with CAE models increases simulation accuracy Easy FRF or mode data set sharing facilitates communication between development groups Modal Coupling solution: synthesized modes for the full assembly. Response signal after applying the loads. 8 LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Transfer Path Analysis LMS Virtual.Lab Transfer Path Analysis is a comprehensive solution with tools to predict and assess system noise and vibration response under operational loading as well as determine acting loads from physical prototype testing data. Using this solution, engineers can perform path or modal contribution analysis to determine the root causes of noise issues and optimize noise and vibration behavior. LMS Virtual.Lab Transfer Path Analysis provides a number of estimation methods to calculate loads that reliably represent realistic customer usage. This includes a direct method to compute forces by multiplying displacement difference over a mount by the frequency-dependent mount characteristic. This mountstiffness method is best used when the connecting stiffness is known, which is the case with engine mounts. The solution also includes an inverse method through which loads are estimated from operational responses. This method is used for relatively stiff connections like suspension bushings that show small displacement differences over the connection. Acoustic loads, such as volume accelerations and volume velocities, can be obtained by using operational pressures and acoustical transfer functions as input for the inverse method. Fast modal and FRF-based response prediction solvers and included path and modal contribution assessment tools provide all the functionality to perform root-cause analyses and target-setting exercises. The responses are visualized using a wide variety of NVH-specific post-processing utilities, and can be compared with pre-defined or imported targets. VL-NVC.36.2 Features Load identification from test or simulation data based on mount stiffness or inverse methods Fast FRF and modal-based forced response solvers Path and modal contribution analysis to determine the root cause of noise and vibration problems Benefits Transparent access to the best available test & CAE data at any time Easy-to-use templates for calculation facility Make accurate predictions more quickly with embedded FRF and modalbased NVH response solvers More insight into structural and acoustical contributions, path and modal contributions Determine loads acting on the structure or strength of an acoustic source using state-of-the-art functionality to estimate operational loads from measurement data Determine acting loads from physical prototype testing data. Response shape and function results. Path contribution displays. Comparison to targets. LMS Virtual.Lab Noise and Vibration 9

LMS Virtual.Lab Ride Comfort and Road Noise Simulation VL-NVC.37.2 LMS Virtual.Lab Ride Comfort and Road Noise Simulation helps users predict operational road noise and perform in-depth analyses to understand the underlying phenomena causing road noise problems. Engineers can study a vehicle s noise and vibration response under partially correlated loads, determine the root causes of noise problems, investigate dominants paths or dominant modes and optimize road noise characteristics in a much more fundamental and quicker way. LMS Virtual.Lab Ride Comfort and Road Noise Simulation contains certain LMS Virtual.Lab Motion modules that helps users set up and solve multibody and flexible body simulations for ride comfort studies. LMS Virtual.Lab Motion can be translated to an equivalent linearized NVH model. Time-domain simulations can also be employed to generate PSDs used as excitation or response data in a road noise study based in the frequency domain. Starting from the assembly dynamics By using power spectral densities or PSDs values, measured or computed excitations or responses can be uncorrelated, or only partially correlated. LMS Virtual.Lab Ride Comfort and Road Noise Simulation offers forced response solvers that provide response PSDs when given excitation signal PSDs. Besides straightforward response computation, users can declare references in a cross-spectral density function set and create deterministic referenced spectra for response signals. This can be done with or without a pre-processing step called Principal Component Analysis (PCA). PCA extracts principal components of partially correlated sources using singular value decomposition. Uncorrelated principal components can be used as input for the fast modal and FRFbased response prediction solvers. Included path and modal contribution assessment tools provide all the functionality to perform root-cause analyses for each principal component. Following a contribution analysis of each principal component, it is possible to recombine the uncorrelated contributions and perform a path contribution analysis on the full set of partially correlated sources, a so-called multi-reference path contribution. Comparable to pre-defined or imported targets, the responses are visualized using a wide variety of NVH-specific post-processing utilities. apply random or partially correlated PSD functions, either user-defined or obtained from simulated or measured time data. Features Create multi-body and flexible body simulation models Uses LMS Virtual.Lab Motion simulation results for NVH analysis loads Import measured operational cross-spectral densities for responses or compute responses using random NVH solvers Create referenced spectra for loads or responses with or without orthogonalizing partially correlated references (Principal Component Analysis) For each reference or principle component, examine contributions of paths or modes to the response and combine effects coming from different references Benefits Obtain a broader view on road noise and ride comfort by incorporating time and frequency simulations Work with test or simulation cross-spectral densities for loads and/or responses Fast and straightforward set-up to process a cross-spectral density set and convert it into a set of referenced frequency spectra Orthogonalize the reference PSDs using Principal Component Analysis (PCA). Study the contributions of transfer paths for each of the principal components. 10 LMS Virtual.Lab Noise and Vibration

LMS Virtual.Lab Noise and Vibration Options VL-NVP.11.2 Load Identification Analysis The Load Identification Analysis module calculates operational forces acting on a system in either a direct way, an inverse way or a combination of both. In the direct or mount stiffness method, the load is computed by multiplying the difference in operating displacement over a mount by its dynamic stiffness. The inverse method computes acting loads by applying the principle that operational responses are due to acting loads. Loads are obtained by inverting the FRF matrix between load application points and operational response locations and by multiplying it by the operational responses. The inverse method is also applicable for acoustical loads, based on operational pressures and acoustical transfer functions. VL-NVP.21.2 Random NVH Analysis The Random NVH Analysis module provides tools to deal with partially correlated signals in the frequency domain. The core data structure is based on cross-spectral densities. Users can compute response cross-spectral densities by using random or partially correlated excitation signals. Besides straightforward response computation, this module enables users to declare references in a cross-spectral density function set and create deterministic referenced spectra for response signals. This can be done with or without a pre-processing step called PCA (Principal Component Analysis). PCA transforms a set of reference signals to orthogonal principal components before computing the response spectra, referenced to the orthogonal principle components. The referenced spectra are later used during a transfer path analysis. VL-NVP.14.2 Modification Prediction Using the Modifi cation Prediction module, users can defi ne elementary modifi cations on a modal or FRF system description. The modifi cation can be an addition of a concentrated mass and a tuned-absorber in a single point or the connection of 2 nodes with a stiffener and/or damper, or even a beam connector. The effect of these modifi cations on the original modes or FRFs is computed in a modal or FRF-based modifi cation case. The resulting new modes or FRFs can be visualized and/or used for subsequent analyses. VL-NVP.23.3 Panel Modal Modification LMS Virtual.Lab Panel Modal Modifi cation helps users to investigate the effect of percentage changes of panel thickness on a structure s modal frequencies and shapes. Combined with LMS Virtual.Lab Optimization, this product can be used to study the sensitivities of vibro-acoustic responses, such as vibration and pressure response levels, towards thickness changes of different panels and to update the structure s panel thickness to meet the required target levels. VL-OPT.xx.x Optimization LMS Virtual.Lab Optimization provides a set of powerful capabilities for single and multiattribute optimization. Through Design of Experiments (DOE) and Response Surface Modeling (RSM) techniques, engineers gain rapid insight in all the possible design options that meet their requirements. Using advanced optimization routines including manufacturing for Six Sigma, LMS Virtual.Lab Optimization automatically selects the optimal design, taking into account real-world variability and meeting the strictest robustness, reliability and quality criteria. LMS Virtual.Lab Noise and Vibration 11

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 advantages. 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 system design. LMS INTERNATIONAL Researchpark Z1, Interleuvenlaan 68 B-3001 Leuven [Belgium] T +32 16 384 200 F +32 16 384 350 info@lmsintl.com www.lmsintl.com Thanks to our technology and dedicated people, LMS has become the partner of choice of more than 5,000 leading manufacturing companies worldwide. LMS is certified to ISO9001:2000 quality standards and operates through a network of subsidiaries and representatives in key locations around the world. For more information on LMS, visit www.lmsintl.com. Worldwide For the address of your local representative, please visit www.lmsintl.com/lmsworldwide