Mobile modal analysis system for identification of modal models from real-life data -
LMS Test.Lab Operational Modal Analysis provides a mobile modal analysis and testing solution for the identification of modal parameters (resonance frequencies, damping and mode shapes). The modal analysis starts from user-selected segments of time data measured on a structure in operating conditions. The time histories are measured using a portable LMS SCADAS 305 front-end, supporting 24 channels for ICP® and Voltage signals and 2 tacho inputs. Any subset of these channels can be used as reference for the operational modal analysis.
The Spectral Acquisition workbook gives feedback on the defined modal analysis parameters, with maximum 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 allows fast generation of wireframe and full 3D visualization of test and modal analysis results. The Operational Modal Analysis workbook offers a powerful method for extracting modal parameters from the time measurements (time data or multi-reference cross powers) and a complete set of modal model validation tools, data re-synthesis and mode shape visualization.
Through the Strip-Chart display, the workbook offers a convenient overview on all input time histories, and allows easy selection of specific data segments for detailed analysis. With the crystal-clear stabilization diagrams from the LMS PolyMAX parameter estimation algorithm, the modal analysis process is significantly simplified and operator-dependency of the resulting modal model (typical for complex, highly damped structures) is eliminated.
