Experimental observation of the initiation process of friction-induced vibration under reciprocating sliding conditions

An initiation process of friction-induced vibration is studied, which are based on three-dimensional vibration accelerations and tangential force of the friction system. Two modes of vibration are founded. Mode one is present as soon as the reciprocating sliding starts. Mode two does not occur until the coefficient of friction reaches a large value. It is found that under certain conditions the normal vibration takes place prior to the tangential vibration with the same or approximate frequency. A wavelet transform technique is applied to extract a quasi steady-state friction force. The result shows that the quasi steady-state friction force is severely changed in the presence of vibration.