An isolator with negative stiffness structures for vehicle torsional vibration

A torsion isolator with negative stiffness structures (NSS) is proposed to isolator the torsional vibration of the vehicle transmission system. This isolator is mounted on the shaft between engine and clutch, so the isolator can filter the torsional vibration from engine to gearbox. In this paper, the restoring torque and stiffness characteristics are studied first. Then the two degrees of freedom nonlinear dynamic equation of this isolation system is established and Harmonic Balance Method (HBM) is performed to obtain the dynamic responses and vibration transmissibility. Furthermore, the corresponding time-history torsional vibration responses under different working conditions are analyzed by numerical simulation method. The dynamic analysis results show that this isolator has greater isolation frequency range than traditional isolator (linear isolator without NSS), and a suitable damping is needed to suppress the resonant response.