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Time Domain Modal Analysis |
At a Glance
-
Basic
Method: Data
driven
Stochastic
Subspace
Identification.
User
choices:
Implementation:
Unweighted
Principal
components,
Principal
Components
and
Canonical
Variate
Analysis.
-
Model
orders: from
one mode to
the size
defined by
the common
SSI input
matrix.
-
Stabilization
criteria:
Natural
frequency
deviation,
damping
ratio
deviation,
mode shape
MAC
deviation,
initial
modal
amplitude
MAC
deviation,
all limits
user
defined.
-
Physical
mode
separation:
Damping
ratio limits
are user
defined.
-
Select and
link: Modes
from the
models
chosen from
each test
setups are
selected and
linked using
snap
functions
and editing
facilities.
-
Uncertainty
estimation:
In case of
several test
setups, the
empirical
standard
deviation is
calculated
for natural
frequencies
and damping
ratios.
The editor of
one of the three
Stochastic
Subspace
Identification
techniques
available in the
ARTeMIS
Extractor Pro.
Accurate
identification
In the time
domain approach
the user can
perform a very
accurate modal
identification
using up to
three different
types of data
driven
Stochastic
Subspace
Identification
(SSI)
techniques. The
techniques use
all response
data available
estimating a
full model in
discrete time.
Flexible
stabilization
criteria
It is possible
to specify a
model order from
one mode to the
maximum number
of modes
determined by
the size of the
common SSI input
matrix specified
in the signal
processing
configuration.
There is an
option to
specify model
stabilization
criteria based
on deviations of
damping ratio,
natural
frequency, mode
shape and
initial modal
amplitude. The
latter describes
the quality of
the statistical
modeling.
Model validation
The user can
validate the
quality of each
model by
selecting the
appropriate tabs
in the window to
inspect either
magnitude or
phase of the
spectral fit or
the fit on the
correlation
function.
Validation plots
are displayed to
show the
(synthesized)
modal model
curves compared
with the curves
directly
obtained from
processed
measurements.
Back to
Technical
Details
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