INVESTIGATION ON FORCED VIBRATION OF STEEL STRING DRIVEN BY ELECTROMAGNET

In this paper, the forced vibration of a steel string fixed at both ends under the action of an electromagnet with alternating current is studied. The spatial distribution of the magnetic field and the lateral force with a Gaussian distribution on the string are simulated, and the vibration of the steel string is calculated based on the non-homogeneous string vibration equation. At the same time, the vibration of string is observed and measured by a self-organized experimental device, and studied from three aspects: the waveform, vibration amplitude and vibration frequency of the forced vibration of the steel string. It is found that here is a stable “standing wave” mode in the waveform of steel string vibration driven by periodic electromagnetic force, and the vibration amplitude of the steel string is significantly attenuated when the driving force frequency deviates from the natural frequency of the steel string. The experimental results show that the vibration frequency of the steel string is twice the frequency of the alternating current of the electromagnet under certain conditions.