( Instability in tensile test. See examples homepage. )

echo -no
number_of_space_dimensions 2
materi_velocity
materi_strain_total
materi_strain_plasti
materi_plasti_kappa
materi_stress
end_initia

start_define
  left_edge   geometry_line 1
end_define
start_define
  lower_edge  geometry_line 2
end_define
start_define
  upper_edge  geometry_line 3
end_define
start_define
  instability_point  geometry_point 1
end_define

left_edge   0 0 0 5 1.e-5
lower_edge  0 0 1 0 1.e-5
upper_edge  0 5 1 5 1.e-5
instability_point  1 0 1.e-5

bounda_unknown 1  -lower_edge -vely
bounda_time    1  0.0 0.0 100. 0.0
bounda_unknown 2  -left_edge -velx
bounda_time    2  0.0 0.0 100. 0.0
bounda_unknown 3  -upper_edge -vely
bounda_time    3  0.0 1.0 100. 1.0

group_type 0  -materi
group_materi_elasti_young 0  210000.
group_materi_elasti_poisson 0  0.33
group_materi_plasti_vonmises  0 0.
group_materi_plasti_vonmises_nadai 0 600 0.21372e-3 0.01
group_materi_membrane 0 -yes

post_node 1 -node_rhside -sum -upper_edge
print_filter 1 -post_node_result 1 -vely

control_mesh_macro                    10 -rectangle 0 5 10
control_mesh_macro_parameters         10 0.5 2.5 1. 5.

control_mesh_refine_globally          20 -p_refinement

(change coordinate of right edge point to trigger instability)
control_data_put                      30  -node -instability_point
control_data_put_double               30  0.99 0.

control_timestep                      40  1.e-4 1.
control_timestep_iterations_automatic 40  0.01 0.1
(
control_print                         40  -time_current -dtime -post_node_rhside_ratio
control_print_history                 40  -post_node_result 1 -vely
)

target_item                            1 -post_node 1 -vely
target_value                           1 -641. 1.e2
end_data
