Vibration measurements and analysis is one of the expertise poles of the Mechanical Measurement Lab. Vibration measurements are performed for predictive maintenance (e.g. PS power generator, LHC cryogenic compressors), validation of Finite Element Analysis (FEA), failure analysis of components (e.g. Pumps, compressors) and to predict the stability of physics detectors in operation. Three techniques are commonly used in this field: Experimental Modal Analysis (EMA), Operating Deflection Shape (ODS) and Order Analysis (OA) in complement of seismic/ground measurements.

Over the last decade, the dynamic behavior of mechanical structures has become more and more important for the stability of CERN equipment’s (e.g. LHC beam stability excited by HL-LHC Civil engineering activities, CLIC project, etc.). For the future project as HL-LHC, FCC and the update of the physics detectors, the vibration issues will become crucial because a high luminosity requests a smaller beam size and a higher vibration stability of the structures. In the particular case of physics detectors, the mass is also minimized in order to minimize interaction with particles; the best ratio between mass and stiffness must be determined by FEA and measurements to obtain the best vibration stability.