Investigations of energy absorption using tuned bistable nonlinear energy sink with local and global potentials

In this paper, a Tuned Bistable Nonlinear Energy Sink (TBNES) considering local and global potentials is implemented to decrease the vibrations of the host structural system. The structural system consists of two coupled linear symmetric oscillators and the nonlinear energy sink consists of a mass-spring-damper which is connected to the ground by means of linear and nonlinear local potentials. Based on Newton's second law, the governing equations of motion are derived. Then, using multiple scales-harmonic balance method, the response of the system for 1:1 external resonance case is extracted and the effects of various parameters on the energy absorption of the TBNES are investigated for both single mode interaction dynamics and complete full dynamics of the system. It is shown that adding potential element greatly impacts on the invariant manifolds of the system. For first mode interactions, implementing any nonlinear local spring leads to limit the stable non-zero domain of the absorber. Furthermore, the absorber performance declines by increasing the nonlinearity of the spring. So, it seems that for first mode excitation the best option is to have a local potential with minimum nonlinearity. But, for the second mode interaction, nonlinear local potential can enhance the absorber performance. In the following, the absorption capability of some famous absorbers are compared and it is obtained that adding local potentials results in greatly increase the absorption performance, especially for second mode interaction of the system. But, it strongly increases the nonlinearity of the absorber's response which makes it unpredictable. (C) 2019 Elsevier Ltd. All rights reserved.