Parameter Research On Chaotic Characteristic Of Isolation Based On Strongly Duffing Model

Machine's periodical vibration does not only cut service life of instrument, but alsodepress its working performance, aggravate constructional element's fatigue damage, reducestructure's stability and load capacity. And it can make bad influence on environment andpeople's living with vibration's contacting propagation and noise's space propagation. In thisthe line spectrum energy on machine's working frequency is on the main position. It has longerduration and more badly destruction power. Nowadays, the most important method ofvibration control is vibration isolation technology based on linear theory. As requisition'simproving of vibration control, it can hardly satisfy the actual need of contemporaryengineering. Therefore vibration isolation technology based on nonlinear theory is becomingbadly needed.Chaos motion is a special phenomena in nonlinear system. The principal of chaoticisolation is to distribute the linear spectrum energy into wide spectrum interval for chaosmotion's power spectrum is continuous distribution. Then the frequency spectrum of vibrationsystem will be changed, and the aim to depress the linear spectrum energy is achieved.Based on nonlinear dynamics, this thesis is focused on chaotic dynamical characteristicof strongly Duffing model isolation, The main research contents of this thesis are listed asfollows:(1)Numerical research method of nonlinear system's chaotic characteristic isdiscussed, research of chaos identification and parameter bifurcation based on stronglyDuffing model is conducted. The distribution characteristic of system's dynamicalcharacteristic on the f ?ωplane is obtained by using standard variance to buildthree-dimension graph of two-parameters bifurcation. The distribution characteristic ofsystem's chaotic characteristic is showed in global view. Furthermore, damping and gravity'sinfluence on system dynamical characteristic distribution is discussed.(2)A nonlinearisolation mounting with adjustable parameters based on strongly Duffing model is designedaccording geometric nonlinear principle. The dynamical parameters of isolation mounting aregot by analytical derivation and experiment. Static and dynamic experiments on this isolationmounting is conducted. The result of experiment and theoretical calculation showed that this isolation mounting is matched with theoretical design.(3)Plane actual model and simplifiedmodels of nonlinear isolation mounting are built by using ANSYS software．Nonlinear staticand dynamic simulation experiment by finite element method is conducted consideringgravity,model error and external excitation noise's influence on strongly Duffing system'skinematic state.In the end, main conclusions are summarized and some disadvantage in researchprocedure is picket-out, and some topics for research prospect are presented.