“…When it comes to unilateral contact, several contact treatments exist in order to compute nonlinear forces. A large majority of the methodologies rely on a penalty-based contact treatment [2,6,7,9,11,18,20,23,31,36,43,44]. For some applications, the latter being too challenging from a numerical standpoint, an additional regularization is added [6,18,43,44] to smoothen the nonsmoothness of contact forces.…”