“…Even local convergence can be ensured locally, both on the normal and tangential problems, it is well known that two‐field or three‐field formulation with Lagrange multipliers can involve spurious oscillations on the dual fields. Indeed, some numerical experiments (depending on the type of finite elements in the bulk, interface discretization, mortar operators, non‐linear behavior along the crack faces, such as friction) and also previous contributions 14, 16–18, 28, 29, 41 clearly illustrate the need to avoid these oscillations.…”