Application of variable excitation frequency for amplitude reduction

Abstract

Dynamic systems are faced with large vibration amplitudes if they operate near the resonance frequency of the system or while passing through the resonance. With a suitable external excitation a reduction of the amplitude of the oscillation can be achieved. The analysis of a variable excitation frequency was first carried out on the force driven single degree of freedom harmonic oscillator. The influence of various excitation parameters can be seen after a mathematical transformation of the excitation signal. The elimination of the natural frequency of the system from the excitation signal is possible with specially selected parameters. It is demonstrated that suitable numerical values, correlations between the parameters and functions allow to reduce the oscillation of the amplitude of the system if the operation takes place near the resonance frequency and also during the resonance passage. The theoretical assertions are validated with an experimental setup and a parameter identification has been made. In addition a worst case scenario is analysed on the test rig. The developed requirements are extended to force driven harmonic oscillators with multi degree of freedom.