Modal Identification and Model Updating of Pleiades

This paper presents all the updating activities performed on the finite element model of PLEIADES. The model updating is usually limited to a correction of modal data, by changing the most sensitive physical design parameters. In this paper, the modelization errors are localized and corrected thanks to a residual energy criteria: the Constitutive Relation Error (CRE). This method was originally developed by the LMT Cachan, and then implemented by the FEMTO Institute (Besançon, FRANCE) for application in an industrial context. The updating of PLEIADES is based on a modal approach: The experimental modes are identified using the Real Time Modal Vibration Identification (RTMVI) method. First, the model of the payload is updated with respect to a subsystem test performed on the instrument. Next, the model is condensed and included in the satellite model. The final step is to update the entire model using tests at satellite level. Primodal, a structural analysis tool developed by TOPMODAL (Toulouse, FRANCE) is used for correlation and updating.