Difference between revisions of "Material Models"
Line 83: | Line 83: | ||
! Name !! ID !! Description !! Pσ !! Pε !! AS !! 3D | ! Name !! ID !! Description !! Pσ !! Pε !! AS !! 3D | ||
|- | |- | ||
| [[Mooney Material|Mooney]] || align="center"| 8 || width=' | | [[Mooney Material|Mooney]] || align="center"| 8 || width='300'|Elastic, isotropic and Ideal Rubber Elasticity | ||
| align="center"| X || align="center"| X || align="center"| X || align="center"| X | | align="center"| X || align="center"| X || align="center"| X || align="center"| X | ||
|- | |- |
Revision as of 10:39, 1 April 2013
Numerous material models are available in NairnMPM and OSUParticulas.
Define a Material
Scripted Input Commands
To use a material in calculations, you first must define it in the input commands. This definition will create a material ID (any string or number) that can be used to assign that material to particles. When using NairnFEAMPM or NairnFEAMPMViz, a material is created with the command block:
Material ID,name,type Property value Property2 value . . Done
where
ID
is the material ID (any string or number) that is used to reference this material in other commands.name
is a name that will appear in output files to describe the materialtype
is the type of material, which can be set by using material type name or material type ID from the available material models (see material tables on this page for each material's name and ID)
Each material property is specified on a line with a property name and its value. Refer to each material type to see the available properties and which ones are required properties. The property names are case sensitive (although NairnFEAMPM can usually handle any case).
XML Input Commands
A material definition in a XML
input file has the form:
<Material Type='1' Name='Polymer'> <Property>value</Property> <Property2>value</Property2> . . </Material>
where
Type
is the material type and must be entered by material type ID corresponding to that material models (see material tables on this page for each material's ID).Name
is any user-defined description of the material.
Each material property is specified in a single XML
element matching the property name and the content of the element as the value. Refer to each material type to see the available properties and which ones are required properties.
Note that in XML
files a material does not have an ID that is used in scripting files to refer to that material in other commands. Instead, other XML
commands refer to defined materials by number or name as follows:
- By Numbers
- In this method, you use
mat='#'
attributes to refer to materials where # is the material number. The materials are defined by numbers in the order they appear in the output file with the first material being number 1. You have to be careful to use the correct number. If you add new materials to a file, it is best to add them to the end of the materials list, otherwise previous commands that referenced materials after an inserted material, will point to the wrong material. - By Name
- In this method, you use
matname='Mat_Name'
attributes where'Mat_Name'
matches theName
attribute of any defined material in the file. You can use these names even before the materials are defined, but an error will occur if you reference materials that are never defined. When referring to materials by name, you must be certain that all materialName
attributes have unique strings.
When referring to materials by name, the defined materials will appear in the output file in the ordered referenced rather than in the order defined in the input file. For this reason, you should not refer to some materials by name and others by number in the same file. The eventual ordering will likely mean the numbers will refer to the wrong material. The naming method is preferred in hand-edited XML
files. If you use both mat
and matname
attributes in a single element, the matname
attribute will be used and the mat
will be ignored.
Linear Elastic Small Strain Materials
The materials in this section are all small-strain, linear elastic materials. They account for rotations by using a hypoelastic correction based on the Jaumann Derivative.
Name | ID | Description | Pσ | Pε | AS | 3D |
---|---|---|---|---|---|---|
Isotropic | 1 | Linear elastic, isotropic | X | X | X | X |
Transverse 1 | 2 | Linear elastic, transversely isotropic with unique axis in the z direction | X | X | X | X |
Transverse 2 | 3 | Linear elastic, transversely isotropic with unique axis in the y direction | X | X | X | X |
Orthotropic | 4 | Linear elastic, orthotopic material | X | X | X | X |
Bistable | 10 | Elastic, isotropic material with two stable states having different properties | X | X | X |
The table columns on the right indicate if each material can be used in plane stress (Pσ), plane strain (Pε), axisymmetric (AS), or 3D calculations.
Hyperelastic Materials
The materials in this section are all large-strain, elastic materials. They account for rotations based on a hyperelastic formulation.
Name | ID | Description | Pσ | Pε | AS | 3D |
---|---|---|---|---|---|---|
Mooney | 8 | Elastic, isotropic and Ideal Rubber Elasticity | X | X | X | X |
IdealGas | 22 | Ideal gas as hyperelastic material | X | X | X |
The table columns on the right indicate if each material can be used in plane stress (Pσ), plane strain (Pε), axisymmetric (AS), or 3D calculations.
Elastic-Plastic Small Strain Materials
The materials in this section are all small-strain, elastic-plastic materials materials. They account for rotations by using a hypoelastic correction based on the Jaumann Derivative. They handle plasticity by combining one of these materials with any compatible Hardening Laws.
Name | ID | Description | Pσ | Pε | AS | 3D |
---|---|---|---|---|---|---|
IsoPlasticity | 9 | Small-strain, isotropic, elastic-plastic material | X | X | X | X |
MGEOSMaterial | 17 | Small-strain, isotropic, elastic-plastic material using a Mie-Grüneisen equation of state. | X | X | X | X |
HillPlastic | 15 | Anisotropic, elastic-plastic material. | X | X | X |
The table columns on the right indicate if each material can be used in plane stress (Pσ), plane strain (Pε), axisymmetric (AS), or 3D calculations.
Hyperelastic-Plastic Materials
The materials in this section are all small-strain, elastic-plastic materials materials. They account for rotations based on a hyperelastic formulation. They handle plasticity by combining one of these materials with any compatible Hardening Laws.
Name | ID | Description | Pσ | Pε | AS | 3D |
---|---|---|---|---|---|---|
HEIsotropic | 24 | Isotropic, hyperelastic-plastic material | X | X | X | |
HEMGEOSMaterial | 25 | Isotropic, hyperelastic-plastic material using a Mie-Grüneisen equation of state. | X | X | X | |
HEAnisotropic | 21 | Anisotropic, hyperelastic-plastic material | X | X | X |
The table columns on the right indicate if each material can be used in plane stress (Pσ), plane strain (Pε), axisymmetric (AS), or 3D calculations.
Viscoelastic Materials
Rigid Materials
Material Class Hierarchy
Materials are C++ classes. The following class hierarchy shows the orginzation of those C++ classes in NairnMPM and OSParticulas. A material in green) is an abstract class that is never assigned to particles. All other are material classes (by their name and their ID in parentheses):
- MaterialBase
- Elastic
- Isotropic (1)
- IsoPlasticity (9)
- MGEOSMaterial (17)
- Bistable (10)
- IsoPlasticity (9)
- Transverse 1 (2) (2.3)
- Orthotropic (4)
- AnisoPlasticity
- HillPlastic (15)
- WOODMATERIAL (19)
- HillPlastic (15)
- AnisoPlasticity
- Orthotropic (4)
- Isotropic (1)
- HyperElastic
- Mooney (8)
- HEIsotropic (24)
- HEMGEOSMaterial (25)
- HEAnisotropic (21)
- IdealGas (22)
- VISCOELASTIC (7)
- RIGIDMATERIAL (11)
- Elastic