Design Of Nonlinear Energy Sink Based On Piezoelectric Drive Control

Automobile is subjected to mixed noises-including tire,wind and engine noises during driving whose frequency ranges from tens to thousands of Hertz which will seriously affect the fatigue of the auto parts and the physical and mental health of drivers.The traditional linear vibration absorber has disadvantages of narrow bandwidth,low attenuation efficiency and large size which is difficult to meet the vibration reduction requirements of low frequency and random vibration of the automobile.In recent years,nonlinear energy sink with advantages of low frequency and large bandwidth attenuation,have great potential applications in the fields of engine vibration reduction,aerodynamic instability reduction of the wing and building vibration reduction.The difficulty lies in that the high efficiency damping efficiency of the nonlinear energy sink is heavily dependent on the external load amplitude,which limits its application in wide frequency domain attenuation.Aiming at the load amplitude dependence problem of bistable nonlinear energy sink,a high-efficiency energy sink with active compensation is proposed,and its dynamic model is established.Specific work includes:(1)The nonlinear energy sink dynamics design model based on linear and bistable composite beam structures is proposed.The attenuation efficiency of nonlinear energy sink under different load is solved based on the Runge-Kutta method.The key parameters of the vibration damping efficiency of the vibration energy sink are obtained by the external load condition(ie the load threshold)of the high-efficiency vibration reduction of the nonlinear energy sink.The results show that the vibration reduction efficiency deviation of the vibration energy sink before and after effective operation reaches 30%;(2)The experimental model of steel cantilever beam and copper bistable beam is designed and fabricated.The nonlinear energy sink based on linear and bistable composite beam structure is established.The experiment platform of electric drive excitation and laser displacement ranging is built.The vibration test of the nonlinear energy sink is carried out.The vibration reduction efficiency of the vibration energy sink is tested and compared with the simulation to verify the correctness of the theoretical modeling.(3)Introducing the piezoelectric drive module,the design scheme of using piezoelectric compensation for external load to achieve the energy sink working threshold is proposed.The dynamic design model of nonlinear energy sink based on piezoelectric compensation is established and effective piezoelectric compensation strategy is proposed which enables the energy sink to achieve high attenuation efficiency under different frequency and load amplitude excitations.