### VT-550 Visual Modal Pro™

The Visual Modal Pro™ package combines the features of the Visual Modal™ package with the features of both the VES-4500 Multi-Reference Modal Analysis and VES-3500 MIMO Modeling & Simulation options.

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 Stabilitydiagram methods for finding modes in data where resonance peaks cannot be counted on Mode Indicator curves.

The MIMO Modeling & Simulation option includes advanced processing features for calculating multiple outputs from multiple time or frequency inputs, and for performing force path analysis by calculating multiple inputs from multiple outputs. Multiple Reference FRFs can also be calculated with this option, along with Multiple and Partial Coherence.

### Multi-Reference Modal Analysis Features

- Mode counting to identify
*closely coupled modes & repeated roots*using either the Multi-Reference Complex Mode Indicator Function (CMIF), or the Multi-Reference Multivariate Mode Indicator Function (MMIF) - Curve fitting using the Multiple Reference Orthogonal Polynomial method
- Multi-Reference 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 a Stability diagram and either the Z-Polynomial curve fitting method, the Complex Exponential curve fitting method, or the Alias-Free Polynomial (AF Poly) curve fitting method
- Stability 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
- Stable Poles A graphical display of poles (frequency & damping estimates) in differently colored stable pole groups
- Stable Pole Group. A group of solutions 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 Component 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 a set of shapes with few DOFs, to create new shapes with many DOFs in them
- Poles A graph of the modal frequency & damping estimates (poles) of a set of mode shapes

### MIMO Modeling & Simulation Features

- MIMO 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
- MIMO Sinusoidal Forced Response. Calculates and displays response (output) shapes caused by multiple sinusoidal excitation (input) forces, using either FRFs or mode shapes to model the system dynamics
- MIMO Force Path Analysis. Calculates multiple excitation force time or frequency waveforms from multiple response (outputs), using either FRFs or mode shapes to model the system dynamics
- MIMO FRFs (Transfer functions). These frequency functions can be calculated from multiple excitation (input) and response (output) time waveforms, using Rectangular or Hanning time domain windows, triggering, linear or peak hold spectrum averaging, and overlap processing
- Multiple and 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), for each frequency. Partial Coherence measures the contribution of each measured excitation force (input) to each measured response (output), for each frequency.
- MIMO FRFs (Transfer functions) can be calculated from multi-channel Auto & Cross frequency spectra