Dynamic Design Of Elastic Support/Dry Friction Damper Matching Rotor

The elastic support/dry friction damper is a new type of damper which is used in active vibration control for a rotor system and has a wide application prospect.Some issues based on the dynamic design of the elastic support/dry friction damper matching rotor were studied systematically and deeply.The single degree of freedom mass-spring system restricted by dry friction force was modeled by using Coulomb friction.The free vibration and forced harmonic vibration of the system were analyzed by analytical solution.The damping effect of dry frictional force for mechanical system was interpreted.The hysteretic dry friction model was developed from one-dimensional relative motion to two-dimensional relative motion by analyzing the two-dimensional relative motion of a ball-plate model.This ball-plate friction model is clear and simple,by which a mechanical system with two-dimensional relative motion of friction can be described conveniently.The dynamic differential equations of the rotor with elastic support/dry friction dampers were derived by using the ball-plate friction model.The whirl motion of the rotor and the gyroscopic moment were considered in the equations.The whole rotor system is with a total of 16 degrees of freedom.The equations give a comprehensive description of the motion of the rotor with elastic support/dry friction dampers.The influence of different design parameters on the damping effect of the elastic support/dry friction damper was studied by solving the dynamic differential equations of the rotor with elastic support/dry friction dampers.Studies have shown that the damping effect of the elastic support/dry friction damper is closely bounded up with the stiffness distribution of the rotor-support system,the location of the damper,the pressing forces between moving and stationary disks,the friction coefficient,and the stationary disk stiffness.In short,the elastic support/dry friction damper performs better in the case of the damper located at the support with higher strain energy;the greater the contact stiffness between moving and stationary disks and the stationary disk stiffness,the better the damper will performs;with a given elastic support/dry friction dampers,there is an optimal pressing force under which the damper performs best.The stiffness coefficient and damping coefficient of the friction force for a rotor at the assumption of circular whirl motion were derived.Based on the transfer matrix method,a calculation method about dynamic response of the rotor with elastic support/dry friction dampers was established by bringing the stiffness coefficient and damping coefficient into the elastic support matrix.And then the dynamic design process of the elastic support/dry friction damper matching rotor was established.An active elastic support/dry friction damper which combined the turn-back elastic support and piezoelectric ceramic actuator was designed and produced.And the characteristics of the damper was measured and analyzed.The exactness and validity of the theoretical analysis model established in this paper and the feasibility of the dynamic design process of the elastic support/dry friction damper were verified by comparison of the experimental curves and the theoretic curves under different pressing forces between moving and stationary disks.The active elastic support/dry friction damper with piezoelectric ceramic actuator designed and produced in this paper has many advantages,such as good damping effectiveness,simple control strategy,compact structure,light weight,and it is very important and necessary to study further about this type of damper.A clear and simple two dimensional friction model(ball-plate model)was established,by which the design model of the elastic support/dry friction damper was established.And then the dynamic design process of the damper matching rotor was established.An active elastic support/dry friction damper which combined turn-back elastic support and piezoelectric ceramic actuator was designed and produced.The validity and feasibility of the dynamic design process were verified by experiments.the experiments results has showed that the damper designed and produced in this paper has very good damping performance,compact structure,simple control strategy,and promising engineering applications.