ARTeMIS Modal Pro - Plugin Modules for Structural Health Monitoring
Pro has a series of plugin modules that are designed for Structural Health
Monitoring (SHM). Below, the modules are presented using measurements from the
Dogna Bridge case study. The organization of the modules is shown in figure
Figure 1: Organization of the plugin modules for ARTeMIS
Modal Pro. There are basically four modules that perform
different types of analysis on long-term measurements that
all rely on the same Data Manager Base Module.
Data Manager Base
measurement file is uploaded into an Analysis Session that is the
container for the particular measurements and the results obtained
from it. The Data Manager Base Module is responsible for the
administration of the Analysis Sessions. It stores and retrieves the
different Analysis Sessions when requested by the analysis modules.
The Data Manager extends the ARTeMIS Modal Pro platform that
basically only handles a single Analysis Session.
Multiple Analysis Sessions.
with saving and loading of measurements and results for each
measurement statistics (Maximum, Minimum, RMS, Median, Mean,
Variance, Skewness, Kurtosis).
definition, allowing automatic processing across all Analysis
Sessions using settings of the Master Session. Includes
automatic SSI modal estimation.
(Alert) services. Visual, sound, email, web service.
module consists of two different damage detection algorithms
that have been developed for long-term monitoring of structures. The
algorithms are robust to the natural change of a structure's dynamic
behavior due to the changes of ambient conditions and can be set up
to not reacting on such changes. The plugin also includes a Control
Chart that, as input, can take a user-definable set of damage
indicators and unify them to a single control value with
corresponding statistical based threshold. This control chart can
automatically notify (alert) when the threshold is being passed
after an analysis. The notification can be sounds, emails or web
service calls to third party systems.
In figure 2, the
damage detection is demonstrated using the Dogna Bridge case study
data. The bridge was measured for a period before damaging it. There
are eight reference measurements that are presented by the first
eight green vertical bars in the diagram. The level of these bars
shows the level of the damage indicators under normal conditions.
From the first six measurements, a baseline (reference) model is
determined by the module, and a threshold is automatically estimated
based on the statistical evaluation of the damage indices of the six
reference measurements. As seen, the last two reference measurements
stay under the threshold which indicates that the bridge is still
undamaged. The remaining 14 measurements are all acquired after the
bridge experienced damage, and the associated damage indicators all
pass the threshold significantly and indicate a permanent damage.
Figure 2: Damage Detection of the Dogna Bridge data. 8
reference (undamaged) measurements indicated with the green
vertical bars staying below the thresholds. 14 measurements
of the damaged bridge that all pass the thresholds
The graphics of the
Damage Detection Module can be dumped to the report generator of
ARTeMIS Modal Pro that allows the production of a report with a
consistent customizable layout.
Classic and Robust
indicator updates when new measurements are uploaded.
Validation for visual validation of the null space estimation of
the reference state model.
Chart unifying damage indicators into a single indicator with a
single statistical based threshold.
Similar to the Damage
Detection Module, the modes of the structure can be presented in a
historical view. The Modal Parameter History Module has been
designed for this. It presents the modal parameters as a function of
the Analysis Sessions. In addition, it can automatically track modes
determined in a reference state. Even though they change slightly in
subsequent Analysis Sessions, the Mode Tracking is capable of
keeping track of them. The tracked modes are presented as modal
indicators that are inter-connected.Pointing at the line with the
mouse allows further information of the particular tracked mode.
In figure 3 below, the
natural frequency of three tracked modes is presented. The two first
modes are reasonable unaffected by the damage whereas the third mode
is heavily influenced and even disappears for a while when damage
Figure 3: Modal Parameter History with automatic Mode
Tracking of three modes. The natural frequency of the first
two modes is quite unaffected by the damage. The third mode
changes and disappears completely during the first set of
damage measurement and reappears again later.
Clicking on a specific
indicator in the diagram will present the corresponding mode in the
Modes List of the Analysis Sessions and start an animation of its
mode shape, see figure 4 below.
Figure 4: Clicking a specific mode indicator will display it
in the list of modes of the specific Analysis Session and
start an animation of its mode shape.
As shown below in
figure 5, the Mode Tracking can also be presented in terms of other
modal parameters such as the damping ratios and mode shapes. In case
of the mode shapes, it will be the Modal Assurance Criterion between
the reference state mode shape and the mode shape of the different
Figure 5: Mode Tracking of three modes presented in terms of
the change of the Modal Assurance Criterion of the modes
between the reference state and the current state. The
highligted mode is the third mode that also has a
significant change of the MAC value as damage occurs.
There is an export
facility that allows the saving of all the modes presented in the
Modal Parameter History window and specific export of the tracked
modes. The graphics of the Modal Parameter History module can be
dumped to the report generator of ARTeMIS Modal Pro that allows the
production of a report with a consistent customizable layout.
presentation of natural frequencies and damping ratios.
of modal parameters to SVS and UFF file formats.
tracking based on the estimation of a set of reference modes
obtained from a specified set of reference Analysis Sessions.
presentation of the tracked modes (Drawn interconnected).
Natural frequencies and damping ratios - absolute and relative
to their reference mode. Modal Assurance Criterion of the mode
shapes relative to the mode shape of their reference mode.
of tracked modes to SVS and UFF file formats.
Drift Analysis Module
The Drift Analysis
Module is designed to analyze interstory drift based on measurements
from sensors located at the top and bottom of structural elements.
These elements can e.g. be columns. If the drift exceeds a certain
percentage of the distance between the sensor locations, the module
will automatically alert in terms of sounds, email or web service
definitions. Each definition specifies two measurement channels
and a relative drift threshold.
Display of sensor
displacements and relative drift time series of selected drift
Visual alerting in
relative drift time series, in the definition table and on the
The Data Acquisition
Module called Automatic File Upload is designed to automatically upload and process measurement
files arriving in designated file folder on the user network. It is
possible to configure the file location and file type as well as the
type of processing that should be initiated after file upload. The
module allows ARTeMIS Modal Pro to fully plug into any third party
physical data acquisition system and to perform automatic data
analysis using any of the above-mentioned analysis modules as well
as the native Operational Modal Analysis techniques of ARTeMIS Modal
upload from a specific folder on a specific interval.
ARTeMIS Modal input file formats.
processing of uploaded measurements.
post processing (Move, Delete, Rename).