BepiColombo: sine test FEM correlation experiences

This paper reflects on some of the experiences of correlating the Finite Element Model (FEM) of ESA's BepiColombo spacecraft to sine sweep test measured data, in order to validate the model for subsequent Coupled Loads Analysis (CLA). Post-model update procedures can take a significant number of man hours to complete, without necessarily resulting in a final FEM which is notably more representative of the real structure than the initial FEM. The long term research intention is to use the lessons learnt from BepiColombo and other spacecraft correlations to work towards the containment of the FEM correlation process, this paper addresses part of this on-going research effort. This is to be achieved through: investigating the current techniques/algorithms for FEM test analysis correlation and validation; identifying their limitations; thus ultimately developing a methodology which identifies where model updates are or are not necessary to achieve a model which is validated for key participating modes in flight predictions or during any sine test notching