Study On The Characteristics And Installation Error Of Collision-Elasticity Enhanced Vibration Absorber Under Simple Harmonic Excitation

Pure cubic vibration absorber has gradually become a research hotspot in recent years due to its two significant advantages of light weight and broadband vibration reduction.Because this type of vibration absorber introduces strong nonlinear factors into the original system,it will also cause bifurcation and jump phenomena in the system,which will lead to the failure of the vibration absorber.Therefore,parameter optimization and bifurcation control are very important in the study of pure cubic absorbers.In this paper,a new type of collision-elasticity enhancement vibration absorber is proposed and its vibration absorption performance under simple harmonic excitation is studied.The main contents are as follows :Firstly,the vibration reduction effects of pure cubic vibration absorber,non-smooth vibration absorber and collision-elasticity enhancement vibration absorber are compared and analyzed.Based on Runge-Kutta method,the amplitude-frequency response and waveform of the main vibration system connecting the first two vibration absorbers are obtained.Subsequently,the velocity attenuation coefficient and piecewise linear damping are introduced to obtain the dynamic response of the system connected with the collision-elasticity enhancement vibration absorber.When the excitation amplitude is small,the performance of the three absorbers is very close.When the excitation amplitude is further increased,the vibration reduction effects of the three are from high to low in order of collision-elasticity enhancement vibration absorber,non-smooth vibration absorber,and pure cubic vibration absorber.When the excitation amplitude exceeds a certain threshold,the pure cubic vibration absorber fails and bifurcation occurs in the system,but the collision-elasticity enhancement vibration absorber and the non-smooth vibration absorber can eliminate the bifurcation phenomenon of the system,and the collision-elasticity enhancement vibration absorber has better suppression effect on the high branch response than the non-smooth vibration absorber.A test platform for connecting a single-degree-of-freedom linear main oscillator with a collision-elasticity enhancement vibration absorber is designed and fabricated.The difference in the acceleration response of the main oscillator connecting the collision-elasticity enhancement vibration absorber and the pure cubic vibration absorber under simple harmonic excitation is compared.The results show that the collision-elasticity enhancement vibration absorber has superior vibration reduction performance and can change the stability of the whole system.In addition,the vibration absorber can also suppress the occurrence of bifurcation,thereby eliminating the high branch response of the system under large excitation.The influence of the spring stiffness of the vibration absorber and the gap between the two parameters on the response of the main oscillator is also analyzed.The test results show that the collision-elasticity enhancement vibration absorber can have better vibration suppression effect by reasonably controlling the two parameters.The influence of positive or negative linear stiffness caused by installation error on vibration reduction effect of vibration absorber is studied quantitatively.The dynamic equation of the system is derived and the amplitude-frequency response curve of the system is obtained by the complex variable averaging method.Then the correctness of the semi-analytical formula is verified by the Runge-Kutta method.The vibration absorber will produce a special double-peak phenomenon when the spring element is pretensioned,but the main oscillator still maintains a resonance peak,that is,the linear stiffness generated by the pretension will not affect the dynamic response of the main oscillator.The low-frequency resonance peak of the vibration absorber disappears when the spring element is preloaded.With the increase of the stretching amount of the spring element,the amplitude of the main vibrator decreases,which is obviously beneficial to vibration reduction.As the compression of the spring element increases,the amplitude of the main oscillator increases,which is obviously not conducive to vibration reduction.It is worth noting that both pre-tension and pre-compression have little effect on the special emphasis response frequency band and high branch response frequency band of the system.