Study On Damping Performance And Vibration Behavior Of Mn-Cu Alloy

Mn-Cu alloys have been widely accepted for its excellent mechanical properties and high damping coefficient,and have a high potential to be applied in the fields of aviation,navigation and automobile.To suppress the vibration and the noise of mechanical systems,it is of great significance to build up a theoretic method design with Mn-Cu alloy.However,how to carry out the theoretical research of the vibration absorber based on the characteristics of the vibration system is still a matter of concern.In this paper,the correlation between the vibration parameters,such as the vibration frequency and amplitude and the damping mechanism of Mn-Cu alloy is analyzed firstly,and then the vibration characteristics of Mn-Cu alloy cushion are analyzed compared with the steel cushion.As a result,the improved scheme was provided the improved scheme.The damping performance of Mn-Cu alloy was investigated using the response decay method.The non-contact acceleration sensor was chosen to avoid the effect of additional mass and boundary constrained damping on the system,consequently achieving a more accurate result.The vibration signal was processed by the band-pass filter.Based on these filtered signals,the average loss factors of one frequency band were calculated.The loss factor of Mn-Cu alloy change from 0.014 to 0.042 within the frequency range of 0-2000 Hz.And the dependency of loss factor on the strain amplitude and frequency is obtained.The result shows that the Mn-Cu alloy's loss factor decreases with the increases of frequency,and increases with the decreases of strain amplitude.The vibration performance of cushion of motor system was analyzed by using ANSYS software.The result based on modal analysis show that the vibration modes and stress of Mn-Cu alloy and mild steel cushion changed with the increase of order.The result of harmony response analysis shows that the vibration mainly occurs along the Y direction,and the amplitude-frequency performance of Mn-Cu alloy cushion is better than that of mild steel cushion.The motor vibration system was designed to measure the motor vibration reaction at three speeds by using Mn-Cu alloy and mild steel cushion respectively.The collected data was processed with the wavelet analysis.And the result shows that the vibration effect of Mn-Cu alloy cushion is better than that of mild steel,and the damping performance of Mn-Cu alloy cushion increases with the increase of rotating speed.The amplitude of vibration reduction is up to 263%when the rotating speed is 4585r/min.The optimization scheme is proposed to improve the low-frequency vibration effect.Three variables were designed to optimize the damping performance of Mn-Cu alloy at lower-frequencies,which were verified by experiments.The result shows that the first-order amplitude is reduced by 16.1%and the second-order amplitude is reduced by 8.6%,which is consistent with the simulation result.