Comparison of the performance and dynamics of the asymmetric single-sided and symmetric double-sided vibro-impact nonlinear energy sinks with optimized designs

The operation of symmetric double-sided and asymmetric single-sided vibro-impact nonlinear energy sinks (DSVI NES and SSVI NES) is considered in this study. The methodology of optimization procedures is described. It is emphasized that the execution of optimization procedures is ambiguous, allows for a great deal of arbitrariness, and requires experience and intuition on the part of the implementer. There are a lot of damper parameter sets providing similar attenuation of the primary structure (PS) vibrations. It is shown that the efficiency of such mitigation for both VI NES types with optimized parameters is similar. However, their dynamic behavior differs significantly. The system with the attached DSVI NES exhibits calm dynamics with periodic motion and symmetrical bilateral impacts on both obstacles. The system with attached SSVI NES exhibits rich complex dynamics when the exciting force frequency is varied. Periodic modes of different periodicity with different numbers of asymmetric impacts per cycle on the PS directly and on the obstacle alternate with various irregular regimes, namely, chaotic mode, intermittency, and crisis-induced intermittency. The regions of bilateral impacts are narrow and located near resonance; they are narrower for a system with an attached DSVI NES. In a system with an attached SSVI NES, there are wider areas of asymmetric unilateral impacts.