ME’scopeVES – Options

Options add various features to the basic VT-620 ME’scopeVES package. Options can be combined to upgrade to more powerful packages and can be ordered based upon your individual needs.

VES-3000 Signal Processing

VES-3000 contains an FFT & Inverse FFT that make it easy to analyze signals and animate ODS’s directly from either time or frequency domain measurements. It includes Notch, Band & Exponential windowing so that selected ranges of data can be analyzed, and unwanted portions removed. It includes waveform Cut, Copy & Paste, waveform integration & differentiation, and a large variety of waveform math and statistics functions.

This option also can be used to calculate Fourier spectra, Auto & Cross spectra, Power Spectral Densities (PSDs), and Spectrograms from time waveforms, using time domain windowing, triggering, averaging and overlap processing.

ODS FRFs, which provide a true measure of the amplitude & phase of each measured structural response, can also be calculated.  A set of ODS FRFs can be used for displaying ODS’s in animation and for Operational Modal Analysis.

Signal Processing Features:

  • Simultaneous FFT & Inverse FFT on all measurements in a Data Block. The FFT will transform any number of samples, and is not restricted to a power-of-2
  • Integration & differentiation of time or frequency signals
  • Cut, Copy & Paste of time or frequency signals
  • DC Removal of time or frequency signals
  • Sort & Select waveforms
  • Notch & Band windows for removing unwanted data from time or frequency waveforms
  • Force & Exponential windows to remove noise and leakage from impulse response measurements
  • Flat Top window for obtaining accurate narrow band signal amplitudes
  • Hanning window for minimizing leakage effects in frequency spectra
  • Calculation of Fourier spectra, Auto & Cross spectra, Spectrograms, Power Spectral Densities (PSDs), and ODS FRFs from time domain operating data
  • Time domain signal processing includes, Rectangular, Hanning, or Flat Top windows, triggering, linear or peak hold spectrum averaging, and overlap processing
  • ODS FRFs can be calculated either from Auto & Cross Spectra or from Transmissibility’s and reference Auto Spectra
  • Order-tracked ODS’s can be displayed directly from multi-channel Order-tracked response only data
  • Waveform Math functions include complex scaling, add, subtract, multiply, divide, conjugate, invert, square, square root, smooth, sum, average, and more on measurement Traces in a Data Block
  • Units conversion and scaling between Linear (RMS) and Power (MS)
  • Measurement scaling between Peak, Peak to Peak, and RMS
  • Waveform statistics (Minimum, Maximum, Mean Squared, RMS, Variance, Standard Deviation, Absolute Deviation, Power, Linear Power, Crest Factor, Skew, Kurtosis)

Shape Processing Features:

  • Shape Integration & differentiation
  • Shape Cut, Copy & Paste
  • Sort & Select of shapes and shape components (DOFs)
  • Shape Product. Shows nodal lines among all shapes when displayed on the structure model

 

 

VES-3500 MIMO Modeling & Simulation

The Multi-Input Multi-Output (MIMO) Modeling & Simulation option includes advanced processing features for calculating multiple Inputs, multiple Outputs or MIMO FRFs.  It utilizes a Multiple-Input Multiple-Output matrix model to calculate the following,

  • Multiple Forced Responses. Multiple time or frequency Outputs waveforms are calculated from multiple time or frequency Input waveforms
  • Force Path Analysis. Multiple time or frequency Input waveforms are calculated from multiple time or frequency Outputs
  • MIMO FRFs. FRFs are calculated from simultaneously acquired multiple Input & Output time waveforms. Multiple & Partial Coherence can also be calculated with MIMO FRFs

Modeling & Simulation Features:

  • Forced Response: Calculates multiple response time or frequency waveforms (outputs) caused by multiple excitation forces (inputs), using either FRFs or mode shapes to model the system dynamics
  • Sinusoidal ODS. Calculates and displays and ODS caused by multiple sinusoidal excitation forces (Inputs), using either FRFs or mode shapes to model the system dynamics
  • Force Path Analysis. Calculates multiple excitation force (Input) time or frequency waveforms from multiple responses (Outputs), using either FRFs or mode shapes to model the system dynamics
  • MIMO FRFs (Transfer functions). These frequency functions are calculated from simultaneously acquired multiple excitation forces (Input) time waveforms, and the multiple response (Output) time waveforms caused by the Inputs. Rectangular or Hanning windowing, triggering, linear or peak hold spectrum averaging, and overlap processing can be chosen during signal processing
  • Multiple & Partial Coherences. These frequency functions can also be calculated together with MIMO FRFs. Multiple Coherence measures the overall contribution of all measured excitation forces (Inputs) to each measured response (Output), at each frequency. Partial Coherence measures the contribution of each measured excitation force (Input) to each measured response (Output), at each frequency.
  • MIMO FRFs (Transfer functions) can also be calculated from multi-channel Auto & Cross spectrum measurements

 

 

VES-4000 Basic Modal Analysis

The Basic Modal Analysis option provides all of the tools you need for extracting modal parameters from experimental vibration measurements (FRFs). With this option you can identify the frequency, damping & mode shape of the modes of a structure from experimental data.

Modal parameter estimation (curve fitting) is done in three steps; 1) count the number of modes using a Mode Indicator function, 2) estimate the modal frequency & damping for each mode, 3) estimate a modal residue (a mode shape component) for each mode & each measurement.

Basic Modal Analysis Features:

  • Mode Indicators for counting modes. Either a Complex Mode Indicator Function (CMIF) or a Multivariate Mode Indicator Function (MMIF) can be calculated and displayed. All of the resonance peaks above a scrollable noise threshold are automatically counted
  • Frequency & damping curve fitting. Either the Local or the Global Orthogonal Polynomial method can be used, with extra polynomial terms to compensate for out-of-band modes
  • Residue curve fitting. Either the Orthogonal Polynomial method or the Peak Cursor method can be used
  • Quick Fit. With one command, all three curve fitting steps are executed with minimal user interaction
  • Frequency & damping estimates are graphically indicated on the Mode Indicator graph
  • A Curve Fit function is overlaid on each measurement to graphically confirm each curve fit
  • Selected measurements and frequency bands can be used to improve your modal parameter estimates
  • All curve fitting data is saved with each measurement
  • FRFs can be synthesized using the parameters of selected modes
  • Modal Assurance Criterion (MAC). A 3D bar chart or spreadsheet display of the MAC values between all mode shape pairs. If MAC = 1, two shapes are the same.  If MAC < 0.9 two shapes are different.
  • Shape Difference Indicator (SDI). A 3D bar chart or spreadsheet display of the SDI values between all mode shape pairs. If SDI = 1, two shapes have the same values. If SDI < 0.9 two shapes have different values
  • Modal Participation. A 3D bar chart or spreadsheet display of the Real part, Imaginary part, and Magnitude of the modal participation factors that result when a set of shapes is curve fit to another set of shapes.
  • Mode shapes can be re-scaled between Residue mode shapes and UMM mode shapes
  • Modal parameters can be imported & exported using the Universal File Format (UFF)
  • Mode shapes can be imported from many third party disk files, including Ansys, Emerson Process Management (CSI), FEMAP, LMS, I-DEAS, NASTRAN, Ono Sokki, Rockwell Automation Emonitor, Spectral Dynamics Star

 

 

VES-4500 Multi-Reference Modal Analysis

The Multi-Reference Modal Analysis option includes advanced Multiple Reference curve fitting methods for extracting the modal parameters of closely coupled modes or repeated roots from multiple reference FRF data. This option also includes Stability diagram methods for finding modes in data where two or more modes are represented by a single resonance peak on a Mode Indicator curve.

Multi-Reference Modal Analysis Features:

  • Mode counting to identify closely coupled modes & repeated roots using either a Multi-Reference Complex Mode Indicator Function (Multi-Ref CMIF), or a Multi-Reference Multivariate Mode Indicator Function (Multi-Ref MMIF)
  • Curve fitting using the Multi-Ref Orthogonal Polynomial method
  • Multi-Ref Quick Fit. Automatically executes three curve fitting steps (count modes, estimate frequency & damping for each mode, estimate residues for each mode) with minimal user interaction
  • Multi-Reference curve fitting using either the Z-Polynomial, the Complex Exponential, or the Alias-Free Polynomial (AF Poly) curve fitting method to estimate stable groups of modal frequency & damping (stable pole groups). All poles are displayed on a Stability diagram.
  • Stability diagram. A graphical display of frequency & damping estimates (poles) in differently colored stable pole groups. All poles are calculated using curve fitting model sizes ranging from 1 to a user-defined maximum model size
  • Stable Poles diagram. A graphical display of poles (frequency & damping estimates) in differently colored stable pole groups
  • Stable Poles Group. A group of poles on a Stability or Poles diagram that satisfy a user-defined minimum number of poles that lie within user-defined frequency & damping tolerances
  • Shape Complexity Plot. A graphical display of the complex shape components of one or more mode shapes
  • Shape Magnitude Ranking. A graphical display of the ordered magnitudes of the shape components of each mode shape
  • Shape Expansion.  A set of shapes with many DOFs is curve fit to one or more shapes with few DOFs, to create one or more new shapes with many DOFs in them

 

 

VES-4700 Operational Modal Analysis

For cases where the excitation forces cannot be measured and output-only responses are acquired, modal parameters can still be extracted from a set of specially processed Cross Spectra or ODS FRFs.

This option adds special windowing and other features to either the Basic Modal Analysis or the Multi-Reference Modal Analysis option, thus providing a complete set of tools for extracting modal parameters from measurements made in any type of testing environment.

Modal parameter estimation (curve fitting) is done in three steps; 1) count the number of modes using a Mode Indicator function, 2) estimate the modal frequency & damping for each mode, 3) estimate a modal residue (a mode shape component) for each mode & each measurement.

Operational Modal Analysis Features:

  • Deconvolution window. When this window is applied to a set of Cross Spectra or ODS FRFs, operational modal parameters can be extracted from them using FRF-based curve fitting methods
  • Modal Model from OMA modes. A modal model (a scaled set of mode shapes) can be created from a set of output-only operational mode shapes
  • Mode Indicators for counting modes. Either a Complex Mode Indicator Function (CMIF) or a Multivariate Mode Indicator Function (MMIF) can be calculated and displayed. All of the resonance peaks above a scrollable noise threshold are automatically counted
  • Frequency & damping curve fitting. Either the Local or the Global Orthogonal Polynomial method can be used, with extra polynomial terms to compensate for out-of-band modes
  • Residue curve fitting. Either the Orthogonal Polynomial method or the Peak Cursor method can be used
  • Quick Fit. With one command, all three curve fitting steps are executed with minimal user interaction
  • Frequency & damping estimates are graphically indicated on the Mode Indicator graph
  • A Curve Fit function is overlaid on each measurement to graphically confirm each curve fit
  • Selected measurements and frequency bands can be used to improve your modal parameter estimates
  • All curve fitting data is saved with each measurement
  • FRFs can be synthesized using the parameters of selected modes
  • Modal Assurance Criterion (MAC). A 3D bar chart or spreadsheet display of the MAC values between all mode shape pairs. If MAC = 1, two shapes are the same.  If MAC < 0.9 two shapes are different.
  • Shape Difference Indicator (SDI). A 3D bar chart or spreadsheet display of the SDI values between all mode shape pairs. If SDI = 1, two shapes have the same values. If SDI < 0.9 two shapes have different values
  • Modal Participation. A 3D bar chart or spreadsheet display of the Real part, Imaginary part, and Magnitude of the modal participation factors that result when a set of shapes is curve fit to another set of shapes.
  • Mode shapes can be re-scaled between Residue mode shapes and UMM mode shapes
  • Modal parameters can be imported & exported using the Universal File Format (UFF)

 

 

VES-5000 SDM (Structural Dynamics Modification)

Once you have identified and quantified a resonance problem in a machine or structure, the next question is, “How can the structure be modified to fix the problem?”

The SDM (Structural Dynamics Modification) method allows you to examine the effects of a variety of potential structural modifications on the resonances of a structure without actually having to make physical modifications.

The resonances (modes of vibration) of a machine or structure depend on its physical properties (geometry, density, elasticity, boundary conditions, etc.). Changing the physical properties of a structure by adding modifications such as stiffeners, brackets, tuned absorbers or other modifications, will directly affect its modes. The SDM method uses industry standard finite elements such as springs, masses, dampers, bars, plates, and solids to model structural modifications. These modifications, together with the modes of the original (unmodified) structure, are used to calculate the new modes of the modified structure.

Because SDM solves an eigenvalue problem in modal space, it calculates new solutions much faster than an FEA Eigen solution method, which solves for modes in physical space.  Hence, thousands of SDM solutions can be evaluated in minutes, which is impossible with an FEA method.

Structural Dynamics Modification Features:

  • Model real world modifications to the structure by adding any number of FEA elements to a 3D model of the structure
  • All visible FEA elements on the structure model are used by SDM. All hidden elements are ignored
  • Either experimental (EMA) or analytical (FEA) modes can be used to model the dynamics of the structure.
  • Modifications are modeled using the following FEA elements; Point masses, linear springs, linear dampers, rods, beams, triangular and quadrilateral plates, tetrahedrons, prisms, and brick solid elements
  • All FEA element properties are displayed and edited in property spreadsheets
  • Modal Sensitivity Analysis. Define a solution space of FEA properties, and calculate new modes that minimize differences between target modal parameters and the new modal parameters
  • Sub-structuring. Connect together two or more substructures using FEA elements, and calculate the modes of the overall combined substructures
  • Tuned absorbers. Model the addition of multiple mass-spring-damper vibration absorbers to a structure, and calculate the new modes of the structure with the tuned absorbers attached

 

 

VES-6000 Acoustics

With the Acoustics option you can post-process and display in animation Acoustic Intensity, Sound Pressure Level (SPL), Sound Power, and ODS’s from either Octave or Narrow Band measurements.  Vibro-acoustic data (acoustics & vibration), can be displayed on the same structure model, thus allowing you to correlate surface vibration with acoustic field measurements.

Acoustics Features:

  • Animated display of vibro-acoustic data (acoustic & vibration)
  • 1/1, 1/3rd, 1/12th, 1/24th octave band measurements are displayed in bar chart format
  • Magnitudes can be displayed in Linear, Log, dB, dB Reference units
  • Acoustic Intensity is calculated from Cross Spectra or time waveforms
  • Sound Power through a surface is calculated from Acoustic Intensity
  • Narrow band can be converted to octave band measurements
  • A, B & C weighting can be applied to narrow band or octave band measurements
  • Noise sources can be ranked in a bar chart based on percentage of overall, dB, or watts.
  • Measurements can be tone-calibrated, using tone magnitude & phase

 

 

VES-8000 FEA Model Updating

With the FEA Model Updating option you can create an FEA model by adding FEA elements to the same 3D model that is used to display ODS’s and mode shapes in animation.

The normal or complex FEA modes of the structure can be calculated from the FEA model. This option includes a library of FEA elements, including springs, masses, dampers, rods, bars, plates, and three types of solid elements. It also includes the FEA Assistant for quickly populating any structure model with FEA elements.

FEA Model Updating Features:

  • FEA Materials Contains material properties (elasticity, Poisson’s ratio, density)
  • FEA Properties Contains properties that can be assigned to FEA elements
  • FEA Assistant. Populates a geometric model with FEA elements.
  • Calculates Normal Modes for models with no damping
  • Calculates Complex Modes for models with damping
  • Calculates Stress & Strain for an FEA model deformed with ODS data.
  • Point matching between FEA and EMA models
  • FEA Model Updating. Define a solution space of FEA properties, and calculate new FEA mode shapes which minimize differences with EMA modal parameters
  • Imports & exports FEA models in a variety of popular third party disk file formats

 

 

VES-7XX Multi-Channel Acquisition

These options add multi-channel data acquisition to any ME’scope package.  They provide setup and control of third party multi-channel acquisition hardware from within ME’scope. All of these options support non-triggered data acquisition.

Many of these options also include Impact testing, if it is supported by the front end hardware.  Time waveforms are simultaneously acquired with the front end hardware, and post-processed by one of these options.  All acquisition and post-processing is set up in a special Acquisition window.

Post-processing includes calculation of Auto & Cross spectra, FRFs & Coherence, ODS FRFs, MIMO (multi-input multi-output) FRFs with Multiple & Partial Coherence, Auto & Cross correlations, Impulse responses.

Acquisition Features:

  • Block-based data acquisition. Number of Samples and Sampling Rate are user-specified but hardware dependent
  • Frequency domain functions. Fourier spectra, Auto & Cross spectra, FRF (Transfer function), Coherence, ODS FRF
  • Time domain functions. Auto & Cross correlation, Impulse response
  • DC removal. Frequency domain removal
  • Spectrum averaging. Stable or peak hold with overlap processing
  • Triggering. Trigger level, double hit line, pre-trigger delay, accept/reject
  • Channels spreadsheet. Acquisition channel properties include transducer sensitivity, transducer units, DOFs, AC/DC coupling, transducer power, time domain window, and more

 

 

VES-7620 Multi-Shaker Signal Output

This option must be used together with one of the VES-7XX options and front end hardware that outputs signals to a shaker.  It can output up to six (6) random or chirp signals for performing a multi-shaker modal test.  Multi-shaker excitation is very effective for testing non-linear structures, and structures that cannot be excited sufficiently with one exciter.  MIMO FRF plus Multiple & Partial Coherence functions are calculated by the VES-7XX option that is compatible with this option.

Multi-Shaker Signal Output Features:

  • Outputs 1 to 6 block-based random or chirp (fast sine sweep) signals
  • Starting & ending frequency of the signals is user-specified
  • Number of samples and sampling rate are user-specified in the VES-7XX option
  • Burst random & burst chirp. User-specified signal shutoff as percentage of block (10 to 100 %)
  • Output signals synchronized with block-based acquisition by the VES-7XX option
  • Output signals time delayed to make them uncorrelated.
  • MIMO FRF plus Multiple & Partial Coherence function calculation done by the VES-7XX option compatible with multi-shaker excitation.