(Solid.
  Force 0.02 on upper nodes.
  Velocity 0 at bottom nodes.
  Young 1..
  In equilibrium, the velocity at the upper nodes
  the stress 0.02 balances the external force)

echo -no
number_of_space_dimensions 2
materi_velocity
materi_strain_total
materi_stress
end_initia

node 1  0 0
node 2  1 0
node 3  0 1
node 4  1 1
element 1  -quad4 1 2 3 4

group_type 0  -materi
group_materi_elasti_young   0  1.0
group_materi_memory 0  -updated_without_rotation

bounda_unknown 1  -ra 1 2 -ra -vely
bounda_time    1  0. 0. 1000. 0.
bounda_force   2  -ra 3 4 -ra -vely
bounda_time    2  0. 0. 0.01 0.01 1000. 0.01
bounda_unknown 3  -ra 1 2 3 4 -ra -velx
bounda_time    3  0. 0. 1000. 0.

print_filter 0 -node_dof -all -vely  -sigyy

control_timestep            0  0.1 0.1
(control_print               0  -time_current -node_dof)

target_item 0 -node_dof 3 -sigyy
target_value 0  0.02 1.e-4
end_data
