Nonlinear Energy Sinks With Piecewise-Linear Nonlinearities

Abstract

Abstract An efficient nonlinear energy sink (NES) is developed here by employing a symmetric piecewise nonlinear coupling force. The proposed piecewise NES has a symmetric clearance about its equilibrium position in which zero stiffness is assumed. However, at the boundaries of the symmetric clearance, the NES is coupled to the linear structure by either linear or nonlinear stiffness elements. The damping is assumed to be continuous linear viscous damping during the oscillation of the NES mass inside and outside the clearance zone. This design is further modified by incorporating a negative coupling stiffness within the clearance zone. Therefore, the performance of the proposed piecewise NESs in rapid vibration suppression is numerically investigated with two-degree-of-freedom spring-mass system and compared with existing NESs in the literature. Accordingly, significant improvement in vibration suppression has been achieved by the proposed piecewise NES compared with other types of existing NESs. Moreover, the numerical simulation results have shown more robustness in the piecewise NES performance for a wide range of stiffness and damping variations than the linear absorber and other types of NESs in the literature.