A study on the damping characteristics of semi-active torsional damper with combined positive and negative stiffness in parallel

A torsional vibration damper with semi-active control based on combined positive and negative stiffness in parallel is presented with its working principle described. The stiffness expression of positive and negative stiffness parallel mechanism is derived and its elastic properties are analyzed. Based on a 2 DOF nonlinear dynamics model for torsional vibration damper established and a control strategy designed, its dynamics characteristics are simulated. The results are compared with that of traditional passive torsional vibration damper with dual mass flywheel, verifying its effects of torsional vibration control.