Um estudo numérico e experimental de um absorvedor dinâmico de vibrações aplicado a um sistema barra-mola amortecido

Abstract

This study addresses the issue of undesired vibration in structures, which is considered destructive and can lead to catastrophic collapses and structural failures due to fatigue. In this context, one of the ways to control these vibrations is through the use of passive dynamic vibration absorbers, composed of elements such as mass, rigidity, and damping. When integrated into the main system, these absorbers can attenuate vibration amplitudes. This work proposes a numerical and experimental study of a passive mass absorber in the form of a pendulum applied to a damped bar-spring system, aiming to determine its effectiveness in vibration control. Analytical expressions for the equations of motion were initially derived for one and two degrees of freedom, both without and with the pendulum absorber, respectively. These equations were the implemented in algorithms using the Matlab software, allowing for the computation of responses in the time domain through the Runge-Kutta method and in the frequency domain through the Fat Fourier Transform. Experimental simulations were conducted to determine the damping coefficient and validate numerically obtained results. Tests were performed for both free and forced vibration, demonstrating satisfactory reductions in amplitudes of up to 100% numerically and 93,5% experimentally. These outcomes underscore the efficacy of using absorbers for vibration control in damped bar-spring systems.