An Experimental Study on a Semi-active Vibration Absorber with an Adjustable Clearance

To increase the range of working frequency of vibration absorbers, a semi-active control strategy is proposed on the basis of a piecewise linear vibration absorber. The range of working frequency of absorber is analyzed with the help of numerical computations. The experimental setup of the semi-active vibration absorber is presented, where the piecewise linearity of elastic component is realized through the use of a clearance adjusted by a step motor and an auxiliary spring switched by an electromagnetic clutch. The motor and the clutch are controlled by a digital signal processor TMS320C30 according to the measured excitation frequency. The experiment has showed that the dynamic performance of vibration absorber could well follow the variation of excitation in both frequency and amplitude.