Keyword type: model definition, material
This option is used to define the properties of a user-defined material. For a user-defined material a material subroutine has to be provided, see Sections 8.5 and 8.6. There is one required parameter CONSTANTS and one optional parameter TYPE.
The value of CONSTANTS indicates how many material constants are to be defined for this type of material. Right now, there is an upper limit of 21 constants for mechanical user-defined materials and 6 for thermal user-defined materials. If you need more, incorporate them in your user subroutine, change the source code, or contact the author to do so.
The parameter TYPE can take the value MECHANICAL or THERMAL. If TYPE=MECHANICAL the user routine characterizes the mechanical behavior of the material, i.e. the stress-strain behavior. This property is only important for mechanical or coupled temperature-displacement calculations. If TYPE=THERMAL the user routine defines the thermal behavior of the material, i.e. the heat flux versus temperature gradient behavior. This is only used in thermal or coupled temperature-displacement calculations. Default is TYPE=MECHANICAL.
The material is identified by means of the NAME parameter on the *MATERIAL card.
First line:
Give on the following int(CONSTANTS/8)+1 lines the constants followed by the temperature value for which they are valid, 8 values per line. The value of the temperature can be left blank, however, if CONSTANTS is a multiple of 8 a blank line must be provided if the temperature is left blank. Repeat the set of constants if values for more than one temperature are given.
Example: *USER MATERIAL,CONSTANTS=8 500000.,157200.,400000.,157200.,157200.,300000.,126200.,126200., 294. 300000.,57200.,300000.,57200.,57200.,200000.,26200.,26200., 394.
defines a user-defined material with eight constants for two different temperatures, 294 and 394.
Example files: beamu.