p_solid

p_solid#

Purpose

Element property function for volume elements.

Syntax

il=p_solid('database ProId Value')
il=p_solid('dbval ProId Value')
il=p_solid('dbval -unit TM ProId name');
il=p_solid('dbval -punit TM ProId name');
model=p_solid('default',model)

Description

This help starts by describing the main commands : p_solid Database and Dbval. Supported p_solid subtypes and their formats are then described.

Database, Dbval, Default, ...#

Element properties are described by the row of an element property matrix or a data structure with an .il field containing this row (see section 7.4). Element property functions such as p_solid support graphical editing of properties and a database of standard properties.

Accepted commands for the database are

d3 Integ : Integ integration rule for quadratic 3D volumes. For information on rules available see integrules Gauss. Examples are d3 2 2x2x2 integration rule for linear volumes (hexa8 ... ); d3 -3 default integration for all 3D elements, ...
d2 Integ : Integ integration rule for quadratic 2D volumes. For example d2 2 2x2x2 integration rule for linear volumes (q4p ... ). You can also use d2 1 0 2 for plane stress, and d2 2 0 2 for axisymmetry.
fsc Integ : integration rule selection for fluid/structure coupling.

For fixed values, use p_solid('info').

For a tutorial on material/element property handling see section 4.5.1. For a reference on formats used to describe element properties see section 7.4.

Examples of database property construction

  il=p_solid([100 fe_mat('p_solid','SI',1) 0 3 0 2], ...
             'dbval 101 Full 2x2x2','dbval 102 d3 -3');
  il=fe_mat('convert SITM',il);
  il=p_solid(il,'dbval -unit TM 2 Reduced shear')
  % Try a smart guess on default 
  model=femesh('TestHexa8');model.il=[]; 
  model=p_solid('default',model)

1 : 3D volume element#

[ProID fe_mat('p_solid','SI',1) Coordm In Stress Isop ]

ProID	Property identification number.
Coordm	Identification number of the material coordinates system. Warning not implemented for all material formulations.
In	Integration rule selection (see integrules Gauss). 0 selects the legacy 3D mechanics element (of_mk_pre.c), -3 the default rule.
Stress	Location selection for stress output (NOT USED).
Isop	Integration scheme. Used to select the generalized strain definition in nl_inout implementations (see section ??). May also be used to select shear protection mechanisms in the future.

The underlying physics for this subtype are selected through the material property. Examples are 3D mechanics with m_elastic, piezo electric volumes (see m_piezo), heat equation (p_heat).

2 : 2D volume element #

  [ProId fe_mat('p_solid','SI',2)  Form N In]

ProID	Property identification number.
Type	Identifier obtained with fe_mat('p_solid,'SI',2).
Form	Formulation (0 plane strain, 1 plane stress, 2 axisymmetric), see details in m_elastic.
N	Fourier harmonic for axisymmetric elements that support it.
In	Integration rule selection (see integrules Gauss). 0 selects legacy 2D element, -3 the default rule.

The underlying physics for this subtype are selected through the material property. Examples are 2D mechanics with m_elastic.

3 : ND-1 coupling element#

  [ProId fe_mat('p_solid','SI',3) Integ Form Ndof1 ...]

ProID	Property identification number.
Type	Identifier obtained with fe_mat('p_solid,'SI',3).
Integ	Integration rule selection (see integrules Gauss). 0 or -3 selects the default for the element.
Form	1 volume force, 2 volume force proportional to density, 3 pressure, 4: fluid/structure coupling, see fsc, 5 2D volume force, 6 2D pressure. 8 Wall impedance (acoustics), then uses the R parameter in fluid.