# Contact patch test (implicit mortar contact, non-matching meshes)

Two unit cubes stacked along z, meshed independently: 3 × 3 × 2 hex8 below (graded in x and y),
2 × 2 × 2 above, so the nodes of the interface at z = 1 do not match. A frictionless contact pair
joins the lower block's top (main) and the upper block's bottom (secondary). The faces x = 0 and
y = 0 of both blocks are symmetry planes, the base z = 0 is held in z, and the top z = 2 is pushed
down by 0.02 (E = 1000, ν = 0.3) in two nonlinear static steps: `Small` without nonlinear
geometry (small sliding, mortar integrals in the reference configuration) and `Finite` with it
(finite sliding, searched and integrated on the deformed faces). The exact state is uniaxial
stress, uniform in both blocks, with a uniform contact pressure equal to it.