( Visco-elasticity test.
  Initially sigxx{0}=1.
  Then visco-elastic creeping is allowed.
  The stress should decrease like
  sigxx = sigxx{0} exp{ time/tm } with tm is the time
  of the maxwell-chain.
  For time=1, tm=1 this leads to sigxx=0.3678 )

echo -no
number_of_space_dimensions 1
materi_velocity
materi_strain_total
materi_maxwell_stress 1
materi_stress
end_initia

node 1  0
node 2  1
element 1  -bar2 1 2

bounda_unknown 0  1 -velx
bounda_time 0  0. 0. 100. 0.
bounda_unknown 1  2 -velx
bounda_time 1  0.  0.  1.e-2 1.e2  2.e-2 0.   100.  0.

group_type 0  -materi
group_materi_density 0  1.0
group_materi_memory 0  -updated_without_rotation
group_materi_maxwell_chain 0  1. 1.

print_filter 0 -node_dof -all -sigxx -1msigxx

control_timestep 0  1.e-2 1.0
(control_print    0  -time_current -node_dof)

target_item  0  -node_dof 2 -sigxx
target_value 0  0.3678 0.01
end_data
