Contact interface dynamics depends on contact surfaces characteristics and the interaction of these surfaces in normal and tangential directions. In fact the interaction in normal direction affects the behavior in tangential direction through changing the size of the contact area. The level of vibration in normal direction is inversely proportional to the contact stiffness in tangential direction and the friction force. In this paper the effects of micro-vibro-impact developing at the boundary of a non-linear beam on the parameters of micro-slip mechanism are studied. Also the variation of the contact stiffness in tangential direction is modeled as a function of vibration amplitude level.