Monday  |  Trinity A  |  04:30 PM–04:50 PM

#14686–Correlation Between Model and Tests of a Three-axis Vibration Control System

Dynamic testing of spacecraft or other objects is fundamental to assess the integrity of the device under test (DUT) and to verify its dynamic behaviour under the same loading conditions of the real operational environment. Accurate replication can be achieved by fixing the DUT on a multi-axis shaker platform and driving the individual shakers via a multiple-input multiple-output (MIMO) vibration controller using the feedback of several accelerometers positioned on the platform and DUT itself. However, the dynamic interaction between the DUT and the test equipment can compromise the performance of the controller and the accuracy of the replication. For this reason, the dynamic behaviour of the multi-axis shaker table should be fully characterised to construct accurate and robust numerical models that in turn can be combined with the finite element model of the DUT to run virtual shaker tests. These virtual shaker tests can then be used to optimally arrange the physical test set-up as well as to fine tune the control strategy to achieve the desired test outcome.

This paper presents the dynamic characterisation of a three-axis shaker table via correlation and update of the numerical model with the experimental measurements of the test equipment. Firstly, the finite element models of the set-up sub-assemblies are derived as well as the lumped parameter models of the electrodynamic shakers. Secondly, both the experimental and numerical modal analysis are conducted on the system sub-assemblies. The correlation between the tests and the models are then calculated following the modal assurance criterion (MAC). Initial discrepancies between the numerical and experimental modes led to a number of model update iterations until the predefined satisfactory level of correlation was reached. Open-loop tests of the physical set-up are then conducted to measure the system frequency response functions between the input shaker voltages and the output table accelerations. These results are finally compared with the numerical co-simulation results of the coupled multi-physical model of the test equipment.

Mattia Dal Borgo   Siemens Industry Software NV
Alberto Garcia de Miguel   Siemens Industry Software NV
Prasanna Chaduvula   Siemens Digital Industries Software
Michael Whiting   Siemens Digital Industries Software
Andrew Santangelo   Siemens Digital Industries Software
Jonas Verhoogen   Siemens Industry Software NV
Mike Neiheisel   Siemens Digital Industries Software
Umberto Musella   Siemens Industry Software NV
Mariano Alvarez Blanco   Siemens Industry Software NV