High channel count system for modal modeling from real-life data -
The LMS Test.Lab Operational Modal Analysis solution identifies modal parameters, starting from user-selected segments of time data measured on a structure in operation. The 96 Channel LMS SCADAS 316 front-end embeds 96 IEEE-1451.4 TEDS compatible channels and supporting, in a single frame, ICP® and Voltage signals. Any subset of these channels can be used as reference for the operational modal analysis. The hardware configuration is tuned for the testing of large objects such as bridges, buildings, airplanes, etc.
The Spectral Acquisition workbook gives feedback on the defined parameters, with validation of the test setup before the actual testing starts. During the measurement, any processing function can be displayed and monitored on-line, while additional information such as rotational speed can also be checked.
The time histories for all channels are directly written to the PC hard disc, simultaneously to the on-line spectral processing, with a throughput performance independent of channel count, acquisition bandwidth and on-line processing.
The Geometry workbook generates wireframe and full 3D visualization of test and analysis results. Through TEDS support, geometry creation is further accelerated with the position information from pre-programmed transducers.
The Operational Modal Analysis workbook extracts modal parameters from response time measurements (time data or multi-reference cross powers) and further privides a set of modal model validation tools, data synthesis and mode shape visualization. With the crystal-clear stabilization diagrams from the LMS PolyMAX parameter estimation algorithm, the analysis process is significantly simplified and operator-dependency of the resulting modal model (typical for complex, highly damped structures) is eliminated.
