On the rocking and walking flat punch: Effect of elastic dissimilarity

• With a constant tangential load, but a rocking normal load, a punch may “walk” or “ratchet”.
• With elastic dissimilarity, we find much higher shift per cycle for given loads, or lower loads to start walking.
• Both elastic shakedown or cyclic dissipation are found, and convergence in this cases is relatively slow.

With an appropriate combination of constant and varying loads, a punch may “walk” or “ratchet”, if rigid body motion is allowed. Here, a full numerical analysis is conducted to study the effect of material dissimilarity on a simple configuration. It is found that walking starts from much lower loads than in the case of similar materials, and higher shift per cycle is predicted with the same load and rocking motion, even accounting for the change of the plane strain modulus. Both elastic shakedown or cyclic dissipation are found, and convergence in these cases is relatively slow, whereas it occurs after 2 cycles of oscillations, in the walking case.