The mode shapes and loss factors of a modular carbon fibre-reinforced plastic (CFRP) composite impeller were determined experimentally and virtually at the component and the impeller level from the validation pyramid. The results are compared with those of investigations on steel reference models and structures. Good correlations were found between the results of the simulation and the experiment of the metallic structures. The similarities were much less marked for the CFRP parts. The damping behaviour of the CFRP impeller is significantly larger compared to steel, mainly due to the modular design.