A novel spring-based nonlinear energy sink for torsional vibration suppression of long-shafting rotor system

In this paper, a novel spring-based nonlinear energy sink (SNES) is proposed for suppressing torsional vibrations in long-shaft rotor systems. The SNES functions by employing a piecewise linear stiffness, which is generated through the extrusion of springs. This mechanism provides the long-shaft rotor system with a restoring torque that can be characterized as a cubic nonlinear force. The paper details the design of the SNES structure and formulates a dynamic model of the SNES-rotor system. Numerical investigations are conducted to assess the vibration damping capacity of the SNES under both transient and steady-state excitations, revealing the nonlinear dynamic behavior of the rotor-SNES system. Furthermore, the effects of various parameters on system performance are examined. Experimental studies on the integrated system demonstrate that the rotor system coupled with the SNES dissipates energy 1.47 times faster than a system without the SNES during transient responses. In terms of steady-state responses, the SNES achieves a vibration suppression rate of up to 52.60% in experiments. These results demonstrate the effective suppression of torsional vibrations in the rotor system by the proposed SNES.