Defining Materials and Media Types

Materials can be defined in Trelis/CUBIT and assigned to element blocks. If an element block is exported without a material assigned to it, a default material (with properties for common steel) will be exported for it.

Create Material [id] [Name <'name'>] [Elastic_modulus <value>] [Poisson_ratio <value>] [Shear_modulus <value>] [Density <value>] [Specific_heat <value>] [Conductivity <value>] [User constants <value ...>] [DepVar <value>]

Modify Material <id_list|'name'|all> [Name <'name'>] [Elastic_modulus <value>] [Poisson_ratio <value>] [Shear_modulus <value>] [Density <value>] [Specific_heat <value>] [Conductivity <value>] [User constants <value ...>] [DepVar <value>]

Create Media [id] [Name <'name'>] [Fluid|Porous|Solid]

Modify Media <id_list|'name'|all> [Name <'name'>] [Fluid|Porous|Solid]

Materials can be created with any number of the following material properties:

Media types include:

Any properties that are not initialized by the user will have a default value of 0.

Materials and media types can be listed and deleted using the following commands:

List Material <id_list|'name'|all>

Delete material <id_list|'name'|all>

List Media <id_list|'name'|all>

Delete Media <id_list|'name'|all>

Materials and media can be added to an existing block using the following command:

Block <id> Material <id|'name'>

Block <id> Media <id|'name'>

Custom Material Commands

The Trelis/Cubit SDK allows custom material properties to be defined using the MaterialInterface. The following versions of the material commands allow users to create materials with custom properties that have already been defined using the SDK.

Create {material|media} 'material_name' property_group 'group_name' [id <requested_id>] [description 'string']

Modify {material|media} 'material_name' [property_group 'group_name'] [id <requested_id>] [description 'string'] [rename 'new_name']
[scalar_properties ('property_name' <property_value>)...]
[vector_property 'property_name' <val1> <val2>...]
[matrix_property 'property_name' <val1> <val2>...]
[clear properties 'property_name1' 'property_name2'...]

A scalar property has a single value associated with it. The scalar properties defined by Cubit are:

Vector properties are given in the command as a list of values. The vector properties defined in Trelis/Cubit are:

Matrix properties are also given as a list of values. The number of columns in the matrix is defined by the specific property, and Cubit automatically divides the given values into rows and columns based on the column count. For example, if a matrix property has 2 columns, the value list "2 33.1 3 18.9" is interpreted as the matrix:

2 33.1
3 18.9


Trelis/Cubit defines the following matrix properties:

A property group is a collection of material properties. Its main purpose is to help define what properties a material should have, even if a value is not given for the property. Trelis/Cubit defines the following property groups:

Table 1. Property groups defined in CUBIT

Property

"CUBIT-FEA"

"CUBIT-ABAQUS"

"CUBIT-CFD"

"CFD_MEDIA_TYPE"     x
"MODULUS" x x  
"SHEAR_MODULUS" x x  
"POISSON" x x  
"DENSITY" x x  
"SPECIFIC_HEAT" x x  
"CONDUCTIVITY" x x  
"THERMAL_EXPANSION" x x  
"YIELD_STRENGTH" x x  
"ULTIMATE_STRENGTH" x x  
"ULTIMATE_STRAIN" x x  
"DEPVAR"   x  
"USER_CONSTANTS" x x  
"ELASTIC_MODULUS_VS_TEMPERATURE"   x  
"POISSONS_RATIO_VS_TEMPERATURE"   x  
"DENSITY_VS_TEMPERATURE"   x  
"YIELD_STRESS_VS_STRAIN_VS_TEMPERATURE"   x  
"SPECIFIC_HEAT_VS_TEMPERATURE"   x  
"CONDUCTIVITY_VS_TEMPERATURE"   x