Predictivity of CNC machine-induced vibrations on inter-story floors based on coupled experimental-numerical investigations

Machine-induced vibrations and their control represent, for several reasons, a crucial design issue for buildings, and especially for industrial facilities. A special attention is required, at the early design stage, for the structural and dynamic performance assessment of the load-bearing members, given that they should be optimally withstand potentially severe machinery operations. To this aim, however, the knowledge of the input vibration source is crucial. This paper investigates a case-study eyewear factory built in Italy during 2019 and characterized by various non-isolated computer numerical control (CNC) vertical machinery centers mounted on the inter-story floor. Accordingly, the structure started to suffer for pronounced resonance issues. Following the past experience, this paper reports on the efficiency of a coupled experimental-numerical method for generalized predictive and characterization studies. The advantage is that the machinery features are derived from on-site experiments on the equipment, as well as on the floor. The experimental outcomes are then assessed and integrated with the support of Finite Element (FE) numerical simulations, to explore the resonance performance of the floor. The predictability of marked resonance issues is thus analyzed, with respect to the reference performance indicators.