Study of the dynamic behavior of cellular structures for the absorption of mechanical vibrations

Abstract

Vibration is a prevalent issue in structural engineering, encompassing a wide array of problems that, if left unaddressed, can lead to severe consequences. These consequences can vary from causing discomfort for pedestrians traversing a perceptibly moving bridge to inducing premature fatigue in aeronautical structural components, ultimately resulting in catastrophic failures and loss of human life. Various sources can induce vibration in structural components, such as misalignment of rotating systems, seismic excitations, road loads on vehicles, and aerodynamic loads. To address these phenomena, in addition to appropriate structural design, various mechanisms, which can operate actively or passively, are used to attenuate oscillatory effects and minimize their impact. Active systems use electronic controllers to generate a response via actuators, reducing the signal transmissibility level based on specific oscillatory signals. Passive systems, on the other hand, mainly rely on viscoelastic polymeric materials, utilizing the reduction of the natural frequency associated with their use and a characteristic phenomenon of these materials for energy dissipation, hysteresis [1]. Hysteresis is a phenomenon where mechanical deformation energy is dissipated in the form of heat. In other words, part of the energy that would be transmitted to the structure is dissipated, thereby increasing the system's damping. Active systems are extremely efficient in their purpose, as they can isolate vibrations across a wide frequency spectrum and can be applied to structures of different magnitudes, from small and lightweight systems using piezoelectric actuators to large structures using hydraulic actuators, such as in active stabilization systems for reducing vibrations caused by seismic activities in buildings. However, they tend to be quite costly and imply an additional layer of systems, which, if not properly designed, can reduce the structure's reliability [2].

Full Paper