1.4. Input file initialization part

The initialization part contains initialization records and an end_initia record

initialization
...
initialization
end_initia

The example below initializes a solid material

echo -yes
number_of_space_dimensions 2
materi_velocity
materi_strain_total
materi_stress
end_initia

The echo (always the first record), number_of_space_dimensions (always the second record), and end_initia record should be supplied always. Use echo -yes to echo the input and echo -no to not echo the input. Use number_of_space_dimensions 1 for 1D problems, etc.. The records materi_velocity`, materi_strain_total and materi_stress create a velocity, strain and stress field in the entire domain. In the following sections, all possible initialization records are discussed. Most of these records create a dof-field, a physical field like a temperature field or a strain field, over the computational domain.

The echo command:

The number_of_space_dimensions command:

List of initialization part records:

1.4.2. echo

First record of initialization part.

Syntax:

echo switch

If switch is -yes the input will be echoed. If switch is -no the input will not be echoed. This needs to be the first record.

1.4.3. number_of_space_dimensions

Second record of initialization part.

Syntax:

number_of_space_dimensions number_of_space_dimensions

Set number_of_space_dimensions to 1 in 1D, etc.. This needs to be the second record.

1.4.4. derivatives

Third record of initialization part, if specied.

Syntax:

derivatives

If this record is included, the time derivative and the space derivatives will be stored in the node_dof records. This is only required for a limited number of models. The model description will specify if this derivatives initialization is needed.

1.4.5. beam_rotation

Syntax:

beam_rotation

The beam rotations \(\phi_{x}\), \(\phi_{y}\) and \(\phi_{z}\) are added to the node_dof records. Please notice that always all three rotations are included. Typically for a 2D calculation You may want to set \(x\) the \(\phi_{x}\) and \(\phi_{y}\) to 0, by using a bounda_dof record.

1.4.6. condif_temperature

Syntax:

condif_temperature

The temperature \(T\) is added to the node_dof records.

1.4.7. groundflow_pressure

Syntax:

groundflow_pressure

The pressure \(p\) is added to the node_dof records.

1.4.8. groundflow_pressure_gradient

Syntax:

groundflow_pressure_gradient

The gradient of the hydraulic pressure \(\frac{ dh }{ dx }\) \(\frac{ dh }{ dy }\) \(\frac{ dh }{ dz }\) is added to the node_dof records.

1.4.9. groundflow_saturation

Syntax:

groundflow_saturation

The groundflow saturation \(S\) is added to the node_dof records.

1.4.10. groundflow_velocity

Syntax:

groundflow_velocity

The ground water flow velocity \(v_{i}^{g}\) is added to the node_dof records.

1.4.11. materi_damage

Syntax:

materi_damage

The damage \(d\) is added to the node_dof records. Also materi_velocity and materi_strain_total should be initialized.

1.4.12. materi_acceleration

Syntax:

materi_acceleration

The accelerations \(a_{i}\) are added to the node_dof records.

1.4.13. materi_displacement

Syntax:

materi_displacement

The displacements \(u\), \(v\), \(w\) are added to the node_dof records. If materi_displacement is initialized, then equations like the convection and diusion of heat equation or the ground water flow equation are evaluated over the deformed volume, which is the sum of the nodal coordinates plus its displacements. Also, if materi_displacement is initialized, the total Lagrange model will be used in stress analysis.

Note

Condition: also materi_velocity should be initialized because the displacement follows from integration of the velocity.

1.4.14. materi_displacement_relative

Syntax:

materi_displacement_relative

Displacements relative to a previous point in the calculation are added to the node_dof records. These are the current displacements minus the displacements before these were changed with timesteps in control_timestep or a displacement reset in control_reset_dof.

For example, this option comes handy when you want to understand the extra displacements caused by the last timesteps.

1.4.15. materi_history_variable

Syntax:

materi_history_variable number_of_variables

Generic history variables which can e.g. be used in some user supplied routines or otherwise.

1.4.16. materi_maxwell_stress

Syntax:

materi_maxwell_stress number_of_chains

Maxwell stress 11 m 12 m 13 m 22 m 23 m 33 m is added to the node_dof records. The parameter number_of_chains should match data item group_materi_maxwell_chain`. The number of maxwell stresses is 6 * number_of_chains`.

1.4.17. materi_plasti_camclay_history

Syntax:

materi_plasti_camclay_history

The history variables \(e_{0}\) and \(p_{0}\) for the camclay plasticity models are added to the node_dof records.

1.4.18. materi_plasti_cap1_history

Syntax:

materi_plasti_cap1_history

The history variable pc for the cap1 plasticity models is added to the node_dof records.

1.4.19. materi_plasti_diprisco_history

Syntax:

materi_plasti_diprisco_history number_of_history_variables

The history variable di Prisco plasticity models are added to the node_dof records. For the group_materi_plasti_diprisco model you need to set number_of_history_variables to 11. For the group_materi_plasti_diprisco_density model you need to set number_of_history_variables to 12.

1.4.20. materi_plasti_f

Syntax:

materi_plasti_f

The plastic yield rule \(f\) is added to the node_dof records. This should only be used for elasto-plastic calculations, and not for visco-plastic calculations.

1.4.21. materi_plasti_f_nonlocal

Syntax:

materi_plasti_f_nonlocal

The nonlocal plastic yield rule \(f_{n}\) is added to the node_dof records.

See also:

See also: nonlocal.

1.4.22. materi_plasti_generalised_ non_associate_cam_clay_ for_bonded_soils_history

Syntax:

materi_plasti_generalised_non_associate_cam_clay_for_bonded_soils_history

The history variables for the Generalised Non Associate Cam Clay for Bonded Soils plasticity model are added to the node_dof records.

1.4.23. materi_plasti_hardsoil_history

Syntax:

materi_plasti_hardsoil_history

The history variable abs(p) for the hardsoil plasticity model is added to the node_dof records. It contains the maximum pressure history.

1.4.24. materi_plasti_hypo_history

Syntax:

materi_plasti_hypo_history

Eight history variables for the hypo-plasticity models are added to the node_dof records. The first history variable -hyhis0 contains the void ratio, and should be initialized by initially specifying node_dof records, or optionally specifying an OCR value with a group_materi_plasti_hypo…._ocr record.

The second history variable -hyhis1 will be filled with the time step size of the hypoplastic substepping scheme; this is meant for postprocessing only.

The third history variable -hyhis2 will be filled with the mobilized friction angle in degrees; this is meant for postprocessing only.

The fourth history variable -hyhis3 will be filled with the a measure of the eective stiness following from the hypoplasticity law ( Mijkl Mijkl ); this is meant for postprocessing only.

The fth history variable -hyhis4 for all laws with the structure option, will be filled with the structure variable s and should be initialized by initially specifying node_dof records.

The sixth history variable -hyhis5, will be filled with the OCR value; this is meant for postprocessing only. This is only available for the group_materi_plasti_hypo_masin_clay and group_materi_plasti_hypo_niemunis_visco laws.

The seventh history variable -hyhis6 for the group_materi_plasti_hypo_wolffersdorf`, will be filled with the density index Id = ec-ed ec-e ; this is meant for postprocessing only.

The eight history variable -hyhis7 for hypoplasticity laws with intergranular strains, will be filled with the intergranular strain variable ; this is meant for postprocessing only.

1.4.25. materi_plasti_kappa

Syntax:

materi_plasti_kappa

The size of the plastic strain is added to the node_dof records. See the theory section (Equations).

1.4.26. materi_plasti_kappa_shear

Syntax:

materi_plasti_kappa_shear

The size of the shear part of the plastic strain shear is added to the node_dof records. See the theory section (Equations).

1.4.27. materi_plasti_phimob

Syntax:

materi_plasti_phimob

The mobilized friction angle mob is added to the node_dof records. It is dened as the angle, in radians, for which the yield function

f = 0.5(2 - 0 ) + 0.5(2 + 0 ) sin(mob ) - ccos(mob )

becomes zero. This is available for mohr-coulomb plasticity only. Please realise that in regions with substantial cohesion the mobilized friction angle mob can exceed the friction angle from the plasticity law. In case of zero cohesion, or cohesion small relative to the stresses, yield is reached if the mob reaches the friction angle. The denition above can give either negative or positive values for mob; negative values simply indicate that the stress state is far away from yielding. The phimob is calculated in degrees.

1.4.28. materi_plasti_rho

Syntax:

materi_plasti_rho

The plastic kinematic hardening vector 11 12 13 22 23 33 is added to the node_dof records.

See also:

See also group_materi_plasti_kinematic_hardening.

1.4.29. materi_strain_energy

Syntax:

materi_strain_energy

The material strain energy 0.5ij ij elas is added to the node_dof records. You can print or plot it to see where energy is stored after loading. Also materi_stress and materi_strain_elasti should be initialised.

1.4.30. materi_strain_elasti

Syntax:

materi_strain_elasti

The elastic strain kl elas is added to the node_dof records.

See also:

See also: materi_strain_total.

1.4.31. materi_strain_intergranular

Syntax:

materi_strain_intergranular

The intergranular strain Sij is added to the node_dof records. This can be used by hypoplasticity laws, see the theory section (Equations).

1.4.32. materi_strain_isa_c

Syntax:

materi_strain_isa_c

The ISA intergranular back-strain Cij is added to the node_dof records. This can be used by hypoplasticity laws with ISA-intergranular strains, see the theory section (Equations).

1.4.33. materi_strain_isa_eacc

Syntax:

materi_strain_isa_eacc

The ISA intergranular accumulated-strain acc is added to the node_dof records. This can be used by hypoplasticity laws with ISA-intergranular strains, see the theory section (Equations).

1.4.34. materi_strain_plasti

Syntax:

materi_strain_plasti

The plastic strain kl plas is added to the node_dof records.

See also:

See also: materi_strain_total.

1.4.35. materi_strain_plasti_camclay

Syntax:

materi_strain_plasti_camclay

The plastic strain kl plas specically for the camclay model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.36. materi_strain_plasti_cap

Syntax:

materi_strain_plasti_cap

The plastic strain kl plas specically for cap models is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.37. materi_strain_plasti_ compression

Syntax:

materi_strain_plasti_compression

The plastic strain kl plas specically for the compression model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.38. materi_strain_plasti_diprisco

Syntax:

materi_strain_plasti_diprisco

The plastic strain kl plas specically for the diprisco model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.39. materi_strain_plasti_ generalised_non_associate_ cam_clay_for_bonded_soils

Syntax:

materi_strain_plasti_generalised_non_associate_cam_clay_for_bonded_soils

The plastic strain kl plas specically for the generalised non associate cam clay for bonded soils model is added to the node_dof records. See also: materi_strain_plasti.

1.4.40. materi_strain_plasti_druckprag

Syntax:

materi_strain_plasti_druckprag

The plastic strain kl plas specically for the drucker-prager model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.41. materi_strain_plasti_hardsoil

Syntax:

materi_strain_plasti_hardsoil

The plastic strain kl plas specically for the hardsoil model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.42. materi_strain_plasti_mohr_coul

Syntax:

materi_strain_plasti_mohr_coul

The plastic strain k:math:varepsilon _{kl} ^{plas} specically for the mohr_coulomb models is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.43. materi_strain_plasti_tension

Syntax:

materi_strain_plasti_tension

The plastic strain \(\varepsilon _{kl} ^{plas}\) specically for the tension model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.44. materi_strain_plasti_vonmises

Syntax:

materi_strain_plasti_vonmises

The plastic strain kl plas specically for the von-mises model is added to the node_dof records.

See also:

See also: materi_strain_plasti.

1.4.45. materi_strain_total

Syntax:

materi_strain_total

The total strain kl is added to the node_dof records. All strains are time integrals of the strain rates for a specic material particle which happens to be present in the node.

1.4.46. materi_strain_total_kappa

Syntax:

materi_strain_total_kappa

The maximum strain size is added to the node_dof records.

1.4.47. materi_strain_total_ compression_kappa

Syntax:

materi_strain_total_compression_kappa

The maximum principal compression total strain as occurred in history is added to the node_dof records.

1.4.48. materi_strain_total_ shear_kappa

Syntax:

materi_strain_total_shear_kappa

The maximum size of the deviatoric part of the total strain as occurred in history is added to the node_dof records.

1.4.49. materi_strain_total_ tension_kappa

Syntax:

materi_strain_total_tension_kappa

The maximum principal tensional total strain as occurred in history is added to the node_dof records.

1.4.50. materi_stress

Syntax:

materi_stress

The stresses 11 12 13 22 23 33 are added to the node_dof records.

1.4.51. materi_stress_pressure_history

Syntax:

materi_stress_pressure_history

The maximum of the absolute value of the pressure which occurs over time is added to the node_dof records. See also group_materi_elasti_stress_pressure_history_factor in the data part.

1.4.52. materi_velocity

Syntax:

materi_velocity

The velocities vi are added to the node_dof records.

1.4.53. materi_velocity_integrated

Syntax:

materi_velocity_integrated

The integrated velocities vii are added to the node_dof records. The integration of nodal velocities in fact results in displacements. But asking for these integrated velocities doesn’t activate automatically that the calculation is done over the total deformed volume (as is the case when you initialize materi_displacement), and not automatically a total Lagrange model is used in stress analysis.

1.4.54. materi_void_fraction

Syntax:

materi_void_fraction

The material void fraction f is added to the node_dof records. This is required for the group_materi_plasti_gurson model.

1.4.55. materi_work

Syntax:

materi_work

The material second order work ij ij is added to the node_dof records. You can print or plot it to see where material instabilities are present.

1.4.56. mrange

Syntax:

mrange maximum_range_length

Sets the maximum filength of ranges -ra … -ra.

1.4.57. mstring

Syntax:

mstring * maximum_number_of_strings*

Sets the maximum number of strings in a define block.

1.4.58. wave_scalar

Syntax:

wave_scalar

Scalar in wave equation is added to the node_dof records.

Note

Condition: also wave_fscalar should be initialized.

1.4.59. wave_fscalar

Syntax:

wave_fscalar

The first time derivative in the wave equation is added to the node_dof records.

Note

Condition: also wave_scalar should be initialized.

1.4.60. end_initia

Syntax:

end_initia

Last record of initialization part.