Evolution of real contact area during stick-slip movement observed by total reflection method
Luo Zhijun, Song Baojiang, Han Jingyu, Yan Shaoze †
       

The force distribution under the lateral friction: (a) the force distribution under only the normal force Fn, (b) the force distribution under the tangential force, where the supporting force p will be distributed non-uniformly to balance the torque caused by the tangential force T.