Mobile system for torsional vibration analysis
The LMS Test.Lab Torsional Vibration Analysis System provides a mobile solution for highly accurate torsional vibration analysis of rotating machinery with single or multiple shafts. The order sections can be extracted from fixed sampled frequency spectra as well as from data sampled synchronously with rpm, giving leakage-free, razor-sharp order cuts. The data acquisition is performed using a portable LMS SCADAS 305 front-end with two embedded tacho inputs, supporting four dedicated torsional vibration channels. Four additional channels for regular ICP® and Voltage signals guarantee data consistency with traditional NVH data. The fast and accurate tacho conditioning, combined with the powerful real time processing power of the QTV module, translates the streams of tacho pulses into highly accurate angular velocity and displacement time histories up to a high bandwidth.
With the Order Tracking during Signature Acquisition workbook, the user can simultaneously acquire narrowband spectra and synchronously sampled order spectra during run-ups, run-downs or sequences of both, referenced to multiple physical tacho channels. Derived tacho enables online monitoring of secondary quantities, such as the rotational speed on other axis or the speed of the vehicle. The many online processing and visualization formats include waterfalls, color-maps and order-, frequency- and octave representations of the torsional vibrations. With the Signal Calculator, the engineer can expand the measurement with virtual time histories, by recombining physical measurement channels using basic and advanced mathematical operations to measure e.g. relative angular displacement. These time histories are calculated automatically upon completion of the measurement and stored together with the measurement channels in the same TDF-data file, so they can be processed simultaneously during the offline throughput processing. Data from different measurement runs can easily be organized for batch processing.
