I-DEAS Modal™ Software
For Processing and Displaying Modal Test Data
m
State-of-the-Art Software for best modal parameter fits. Modes ence frequency domain mode shape
Experimental Modal Analysis curve fit with different number of estimation method can be used with
I-DEAS Modal software provides test poles may be selected and com- other methods for estimating the fre-
engineers with comprehensive capa- bined into a single data set. quencies and damping (such as the
bilities for processing modal test mea-
Local modal parameter and shape time domain polyreference method).
surements and displaying the modal estimation: Search peaks and SDOF
Shape and calculations: Modal
analysis results. It includes capabilities polynomial provide a fast method shape normalization and modal
for modal parameter estimation and for widely separated modes. Circle mass calculations.
data display on geometry including fitting is particularly useful for very
Validation: Synthesis (cursor-pick
animation, graphing function data, lightly damped structures. Complex geometry to synthesize frequency
math processing, data access and exponential provides a basic MDOF response function and compare to
management, and open architecture fitting method. measurement), and modal assurance
and interfacing. The modal test mea-
Global modal parameter and shape criteria (quantitative method for
surements can be obtained using estimation: Methods for single refer- determining the linear indepen-
I-DEAS Standard Measurement™ soft- ence data include the direct parame- dence of mode shape pairs and 3D
ware or transferred from third-party ter frequency domain algorithm graphs of results).
data acquisition software. Specialized which is very stable for narrow
capabilities for test/finite element band applications. Geometry-Based Data Displays
analysis correlation are available with
Methods for single or multiple refer- Presenting data measured at many
I-DEAS Correlation™ software. I-DEAS ence data include polyreference, a locations on the structure using a
Structural Modification™ software classical time domain algorithm with geometry-based display can provide
allows the effects of simple structural wide-frequency band application. a very efficient way of understanding
changes to be evaluated. Orthogonal polyreference provides and communicating the test results.
a wider frequency band application The extensive geometry display capa-
Modal Analysis than the direct parameter method bilities of the system are leveraged to
I-DEAS Modal software provides a and supports data with uneven and provide convenient ways of displaying
complete set of tools for estimating the even frequency spacing. test data. Special features such as an
modal model to describe the vibra- Computational roots within intelligent, adaptive cursor highlight
tional behavior of a structure. Different frequency band are minimized. the geometry attribute of interest as
modal parameter (resonance frequen-
Frequency and damping it traverses the screen.
cies, damping, and residues) and estimation: To provide additional The Model Preparation task provides
mode shape (coefficients of structural flexibility, a global, multiple refer- easy-to-use methods for constructing
deformation) estimation methods
cover the full range of test situations
and structure types.
Mode identification: The mode indi-
cator function is a single plot identi-
fying all of the modal frequencies. It
is produced from operations per-
formed on a global set of frequency
response function measurements.
This aids in locating local modes,
evaluating force input points, and
determining modal density. The nor-
mal mode indicator function identi-
fies modes from single reference
modal tests. The multivariate mode
indicator function identifies modes
from multiple reference tests, includ-
ing repeated modes, and yields nor-
mal mode force patterns.
Selecting Fits: The pole stability dia-
gram can be used with mode indica- Advanced graphics displays help you better understand and communicate
tor functions to cursor-select the modal analysis results.
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geometry appropriate for testing ported devices and shaded image deformed geometry providing a
applications. Geometry can be con- animation is available on certain clear understanding of the response
structed using features such as: advanced graphics devices. measurement as a function of time.
Creation of test measurement points
Arrow and criterion plotting: Vector
Animation of order tracking mea-
(nodes) by keyboard entry and arrow plots of data at nodes and surements: Order track data from
copy, reflect, interpolate, and cursor criteria plots showing data above, rotating machinery tests can be
picking measurement points from a below, within, or outside a defined animated on geometry with the full
detailed finite element model. range are available. range of animation features includ-
Global and local coordinate systems
Contour displays: Data at nodes ing wireframe, hidden line removed,
in Cartesian, cylindrical, or spherical can be displayed on geometry and shaded image displays. The
systems are supported. Local systems using either line or color contours. responses at a specified order and
can be used to account for off-axis You control up to 78 contour levels rpm or the total response can be
measurements. and intervals. animated.
Tracelines provide for wireframe
Transient animation: Displays of
displays. transient events defined from time Prerequisite
Surfaces may be defined for advanced histories can be animated on I-DEAS Core Test
hidden line removed and shaded
image displays and animation.
Groups of measurement points on
different regions of the geometry
can be defined to automate data
processing/display.
A forms- and icon-based user interface
allows the results to be easily applied
to the display of test results on geome-
try. Results from modal analysis, order
track tests, operating tests, or any
other type of vector data at measure-
ment points can be displayed.
Geometry plotting: Deformed geom-
etry plotting and animation for sin-
gle or multiple viewports.
Line, shaded displays: Wireframe,
hidden line removed, and shaded
image deformation displays are
available as static plots on all sup-
ported graphics hardware devices.
Wireframe and hidden line removed The pole stability diagram can be used with mode indicator functions to select
animation is available on most sup- the best modal parameter fits.
MTS Systems Corporation Specifications subject to change without notice.
14000 Technology Drive © 1998 MTS Systems Corporation
Eden Prairie, MN 55344-2290 MTS is a registered trademark of MTS Systems
612-937-4555, Fax 612-937-4515 Corporation. I-DEAS, I-DEAS Modal and I-DEAS Master
E-mail: info@mts.com Series are trademarks of Structural Dynamics
www.mts.com Research Corporation.
300231-01 I-DEASMODAL-01 Printed in U.S.A. 1298
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