Vibration Control And Dynamic Of Enhanced Lever-type Nonlinear Energy Sinks

In this paper,two kinds of enhanced lever-type nonlinear energy sinks are proposed based on the traditional lever-type nonlinear energy sinks:a lever-type parallel nonlinear energy sink and a lever-type series nonlinear energy sink.Firstly,the vibration suppression of a whole star system with lever-type parallel nonlinear energy sink is studied.The amplitude-frequency response curves of the system are obtained based on the harmonic balance method and the pseudo-arc length extension method.The influences of mass,nonlinear stiffness and position of the lever-type parallel nonlinear energy sink on the amplitude-frequency response of the system are studied.The variation of vibration absorption performance of the single and parallel lever-type nonlinear energy sink after the disappearance of isolated annular resonant response.The results indicate that the vibration absorption performance of the lever-type parallel was better than of the lever-type single nonlinear energy sink under the same additional mass condition.Secondly,the vibration suppression of a whole star system with a lever-type series nonlinear energy sinks is studied.By analyzing the influence of the parameters of the lever-type series nonlinear energy sinks on the amplitude-frequency response curve of the system,it is found that the nonlinear energy sink with appropriate mass in series can avoid the appearance of isolated annular resonant response.The vibration absorption performance of the lever-type parallel nonlinear energy sink and the lever-type series nonlinear energy sink are compared and studied with the same additional mass condition.The simulation results show that the vibration absorption performance of the lever-type series nonlinear energy sink is better than that of the lever-type parallel nonlinear energy sink.Finally,based on the Runge-Kutta method and Poincare mapping,the complex dynamics of the whole star system with a lever-type series nonlinear energy sink is analyzed.The effect of the parameters of the lever-type series nonlinear energy sink on the global bifurcation of the system is studied.The results show that the introduction of a lever-type series nonlinear energy sink may complicate the dynamic characteristics of the system.