Re: [Tochnog-users] simulating thixo

[Arturo di G. <art...@in...>]

Il mer, 2002-07-10 alle 10:07, an...@in... ha scritto:
> I believe that plastic deformation is near zero so I think that I can 
> simulate visco-deformation like I fluid flow with very high viscosity, 
> but in this case is correct using mesh_fixed_in_space?

Doesn't the file you submitted use mesh -follow_material? I read on the
manual that this is the default as long as you don't require
materi_displacement in initialization part.

> Last question: how to use gravity load?

force_gravity ...
and eventually
force_gravity_time ...

I think they are internally converted to force_element_volume for each
element.

About your input file:

Young: 74 Gpa -> 74.0e+9 N/m^2

Here is a slightly modified input file: 64 elements, reduced force, very
short time steps, no viscoplasticity for negative values of yield
function, and still diverges after 11 steps. It seems to flow to fast
(divergence of velocity values). Any news?

Arturo

----------------------------------------

echo -no
number_of_space_dimensions 2
materi_velocity
materi_strain_total
materi_strain_plasti
materi_stress
end_initia

options_inertia -no

geometry_line    0  0.0  0.0    0.15  0.0    0.01

geometry_line    1  0.0  0.15   0.15  0.15   0.01

(fixed border)
bounda_unknown 0  -geometry_line 0 -velx -vely
bounda_time    0  0.0 0.     1. 0.

(shear force)
force_element_edge 1 30.0 0.0
force_element_edge_geometry 1 -geometry_line 1

group_type 0  -materi
group_materi_density 0  2670 (2.67 g/cc)
group_materi_elasti_young 0    74000.0e+6 (74000 MPa)
group_materi_memory 0  -updated_without_rotation
group_materi_plasti_tension 0 0.1    (in thixotropic state yeld stress
is 
near 0)
group_materi_plasti_visco_power 0  1.0e-5 1. 10. 
group_materi_plasti_visco_always 0 -no

(control_mesh_macro index macro_item element_group n n)
control_mesh_macro  0 -rectangle 0 9 9

control_mesh_macro_parameters   0  0.075 0.075  0.15 0.15

(control_timestep index step_size time_increment step_size
time_increment)
control_timestep 0  0.0001 1.
control_print_gid 0 -yes

end_data

--------------------------------------------


-- 
Arturo di Gioia
Dipartimento di Ingegneria Meccanica e Strutturale
Universita' degli Studi di Trento

v. Mesiano 77
38100 Trento
ITALY

tel (office)  : 0039 461882525
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