( Solid.
  The velocity field causes a linear xx-stress distribution,
  with stress -1 in the lower fiber and stress +1 in the upper fiber.
  The moment due to this stress is the integral, from x=-1 to x=+1,
  from sigxx * y * dy ; this gives 2/3.
  Only two points over the height are needed to find this moment.
)

echo -no
number_of_space_dimensions 2
materi_velocity
materi_strain_total
materi_stress
end_initia

options_stabilization -no
options_mesh -fixed_in_space -fixed_in_space

node 1  0 0
node 2  2 0
node 3  0 2
node 4  2 2

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 0  -all -vely
bounda_time    0  0. 0. 100. 0.
bounda_unknown 1  -ra 1 3 -ra -velx
bounda_time    1  0. 0. 100. 0.
bounda_unknown 2  2 -velx
bounda_time    2  0. -2. 100. -2.
bounda_unknown 3  4 -velx
bounda_time    3  0. +2. 100. +2.

print_filter 0 -node_dof -all -sigxx
print_filter 1 -post_line_dof -all -sigxx

post_line 1  2. 0. 2. 2.
post_line_n 1  2
post_line_moment 1  -yes

control_timestep  0  1. 1.
(control_print    0  -node_dof -post_line_dof )

target_item  1  -post_line_dof 1  -sigxx
target_value 1  0.6666666666 1.e-4
end_data
