True solution of the ploughing friction coefficient with elastic recovery in the case of a conical tip with a blunted spherical extremity

The ploughing friction occurs when a hard tip moves on a surface. The elastic recovery tends to reduce this ploughing part of friction and this is something that has to be taken into account. Models which allow to evaluate the ploughing friction with elastic recovery for perfectly conical tips are based on an approximation. Here we present the true solution of the ploughing friction with elastic recovery for conical tip and conical tip with blunted spherical extremity.