Analysis of vibration suppression effect of parallel combined damping NES system on non-smooth system

In this paper, the dynamics modeling and vibration suppression analysis of a nonsmooth system with coupled parallel combined damping NES system is carried out. First, the mechanical and mathematical models of the system are established, and the functional expressions of the nonsmooth terms are given. Second, the damping effect of the parallel combined damping NES under impulsive excitation is analyzed, and the damping effect of the parallel connection under different excitation intensities is analyzed by using the comparison of time response and energy change, as well as the influence of the NES parameters on the vibration suppression situation of the system. Finally, the vibration-damping effect exerted by the parallel combined damping NES under random excitation is analyzed, and the influence of the NES parameters is analyzed on the basis of the probability densities of displacement and energy. The results of the study show that the parallel connection provides better damping performance than a single connection, both under impulsive excitation and under random excitation, and that the optimal value of the system mass ratio is not 0.1 under this connection; it is also found that, under both forms of excitation, the parameter values of the NES are not taken to be larger, the better the damping effect suffered by the main system, but that there exists an appropriate range of values. This study is an important theoretical guide for the engineering application of multi-degree-of-freedom NES.