Novel power-sine arch nonlinear energy sink: design, dynamic modeling and torsional vibration suppression performance

Torsional vibration suppression has always been a tough bottleneck restricting the stable operation of rotating machinery. Conventional torsional nonlinear energy sinks (NESs) adopt discrete multi-component structures, which inevitably introduce multi-body friction and parasitic linear stiffness, and their stiffness characteristics cannot be flexibly tuned within limited installation space. This work proposes a novel quasi-zero stiffness (QZS) torsional NES based on geometric nonlinear deformation of power-sine arches. Symmetric pre-compressed arch units are utilized to generate purely geometric nonlinear stiffness within the absorber. This structural design eliminates frictional energy loss inherent in traditional configurations and achieves a broad and stable QZS operating range. Two dynamic models, including a two-degree-of-freedom rotor system and a multi-degree-of-freedom gear transmission system integrated with the proposed NES, are constructed to analyze its vibration reduction capacity. Quasi-static compression experiments validate the accuracy of the finite element model. Torsional vibration bench tests further demonstrate that the proposed NES can effectively suppress the primary resonance peak during speed acceleration, deliver favorable broadband vibration attenuation and significantly delay the onset of resonance. Under steady-state resonant operating conditions, the absorber achieves remarkable vibration attenuation. It can act as a lightweight and high-stability passive vibration mitigation solution for various rotating machinery.