MATUSR

Bulk Data Entry Defines material properties and parameters for user-defined structural material.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MATUSR MID PARAM1 VALUE1 PARAM2 VALUE2 PARAM3 VALUE3
PARAM4 VALUE4 etc.
etc.
PROPERTY PROP1 PROP2 PROP3 PROP4 PROP5 PROP6 PROP7
PROP8 etc. TEXP1 TEXP2 etc. TEXP6
FIELD DENSITY ASSIGN ID

Example 1

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MATUSR 12 USUBID 5 NDEPVAR 1 EXPAN ISO
DENSITY 0.25
PROPERTY 210000.0 0.4 320.0 500.0 0.0 180.0 1.2e+2
1.2e-6

Definitions

Field Contents SI Unit Example
ID Each MATUSR Bulk Data Entry should have a unique ID.

No default (Integer > 0)
USUBID User subroutine ID. This allows you to define different types of material properties. This value corresponds to the idu variable in the user subroutine.

Default = Blank (Integer > 0)
NDEPVAR Number of user-defined state variables. This value corresponds to the nstate(*) variable in the user subroutine.

Default = 0 (Integer ≥ 0)
EXPAN Thermal expansion coefficients type defined on the TEXPi fields of the PROPERTY continuation line. 5
ISO (Default)
Isotropic material.
ORTHO
Orthotropic material.
ANISO
Anisotropic material.
GROUP User-defined group specified on the group argument of the LOADLIB entry. This field is used to identify the LOADLIB entry to load the corresponding .dll.

(Character String)
DENSITY User-defined density.

No default (Integer > 0)
PROPERTY Indicates that user-defined material property data are to be defined in the subsequent fields. Thermal expansion coefficient data are defined at the end of the property data. 3 4 5
PROPi User-defined material property data. These values correspond to the props variable in the user subroutine. nprops variable in the user subroutine defines the total number of properties defined via the PROPi fields.

Default = blank (Real)
TEXPi Thermal expansion coefficient(s). TEXPi data starts at the end of the PROPi data. The number of TEXPi values depends on the EXPAN field option. 5

Default = blank (Real)
FIELD This dictates that the “nprops” variable in the usermaterial subroutine includes the total number of properties defined via the PROPi fields, and, additionally, it includes the number of thermal expansion parameters and the density. 11
DENSITY Indicates that the elemental densities from the .h3d from Inspire PolyFoam file will be mapped to the current grid.
ASSIGN Indicates that the ASSIGN, H3DRES file identification number is to follow.
ID ASSIGN, H3DRES file identification number.

Comments

  1. For more information, refer to User-Defined Structural Material and Build External Libraries in the User Guide.
  2. The corresponding dynamic linked libraries (.dll or .so) for the user-defined material is loaded based on the LOADLIB entry. If LOADLIB entry is not defined (or if the GROUP parameter is not specified), then OptiStruct loads the umat.dll or umat.so file from the working directory.
  3. All parameter and value pairs listed before the PROPERTY continuation line are in free format. Therefore, the pair of parameter name and its value can be located anywhere in the defined fields.
  4. The PROPi and TEXPi data are directly passed to the loaded .dll or .so file where it used by the subroutine identified by the USUBID parameter.
  5. If EXPAN parameter is defined, then the final one (ISO), final three (ORTHO), or final six (ANISO) PROPi values are used as the corresponding thermal expansion coefficients.
  6. MATUSR is supported for Large Displacement Nonlinear Static and Large Displacement Nonlinear Transient Analysis. For Small Displacement Nonlinear Analysis and Linear Analysis, only the linear section of the user-defined material is utilized in the solution.
  7. MATUSR supports deformation gradient tensor for Large Displacement Nonlinear Static and Large Displacement Nonlinear Transient Analysis. The deformation gradient is only supported for the nonlinear section of the user-defined material. Deformation gradient tensor is currently supported for solids and continuum shells (PCOMPLS) elements.
  8. MATUSR also supports an option to assign defined labels to state variables. This can be accomplished by using the initusr subroutine. State variables are defined variables to output the non-standard results in an H3D file. By using the initusr subroutine you can specify the label of the state variable to display in the H3D file.
  9. MATUSR is currently supported for solid elements, referenced via PSOLID Bulk Data Entry, and shell elements referenced by PSHELL or PCOMP Bulk Data Entries.
  10. Shared libraries (.dll or .so) can be created using either Fortran, C or C++ for user-defined materials.
  11. The FIELD continuation line must be included to map the density values from the Inspire PolyFoam h3d file to the current grid. If FIELD is not mentioned, the nprops value is the same as the total number of PROPi values. Examples of “nprops” value with and without FIELD continuation line are defined below.
    • In the following example, nprops=2. “usermaterial” subroutine can only access props(1)=210000.0 and props(2)=0.3 and can not access the thermal expansion and the density.
      Figure 1.


    • In the following example, nprops=4. “usermaterial” subroutine can also access the iso-thermal expansion as props(3)=1e-5 and the density as props(4) (density will be read in by the H3D file ASSIGN).
      Figure 2.