This section describes the available options for mapping of material properties for *MAT_ANISOTROPIC_ELASTIC PLASTIC (*MAT 157). The initial input is the same as the previous section, but with minor changes on the target options, and additional cards that are specifically for initializing material properties for (*MAT 157) with the *INITIAL_STRESS_SOLID card.
This section covers:
| TargetMaterialModel = 157 |
Specify the target material model corresponding to the LS-DYNA application’s material model manual [20]. The only available option here is 157. |
| MapStress = YES |
Define whether *INITIAL_STRESS_SOLID cards are written. If data should be made available for the *MAT 215 material model via *INITIAL_STRESS_SOLID cards, this option must be YES. |
| MapMainDir = NO |
Activate mapping of the main directions to *ELEMENT_SOLID_ORTHO cards. For usage with *MAT_215, this option is NO. |
| ETYP = INT |
1 - Reduced integrated solid elements. 2 - Fully integrated solid elements. This accounts for hexahedral elements as well as for tetrahedral elements. ETYP = 1 activates the mapping to reduced integrated tetrahedral elements (LS-DYNA application ETYP 10 or 13), while ETYP = 2 activates the mapping to fully (4-point) integrated tetrahedral elements (LS-DYNA application ETYP 4, 16 or 17). The number of integration points for tetrahedral elements can also be changed with NIPTETS (see option below). |
| NIPTETS = INT |
1 - Activates mapping to 1-point tetrahedral elements (LS-DYNA application ETYP 10 or 13). 4 - Activates mapping to 4-point tetrahedral elements (LS-DYNA application ETYP 4, 16, or 17). 5 - Activates mapping to 5-point tetrahedral elements (LS-DYNA application ETYP 4, 16, or 17). |
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MapWeldline = YES NO |
Define if weldlines are considered within the mapping. You must provide the respective Moldex3D *.nwd file. If MapWeldline = YES, define the following two cards: WeldlinePID and WeldlineRADIUS. |
| WeldlinePID = INT | Define the part ID that is assigned to weldline elements. |
| WeldlineRADIUS = DOUBLE | Define the radius for the weldline elements. This option enables adjusting the weldline radius so that the number of elements within the weldline zone can be distinguished and assigned weldline PIDs. If this option is not defined, Search Radius and Scale SearchRadius options are used to determine weldline zone. |
| IHIS = INT |
Flag that defines the material parameter written to *INITIAL_STRESS_SOLID cards for *MAT_157, according to [20]. The following values are supported: |
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IHIS = 1 - q-values are written to the first six history variables. | |
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IHIS = 3 - q-values are written to the first six history variables, tensor components Cij are written on history variables #7 - #27. | |
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IHIS = 11 - q-values are written to the first six history variables, tensor components Cij are written to history variables #7 - #27, table IDs for strain rate dependent plasticity are defined in history variable #28. | |
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For IHIS = 1, no further input is required. | |
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If IHIS > 1, define the following variables: | |
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HomogenizationMethod = Halpin − Tsai Tandon − Weng Voigt Kukuri Mori − Tanaka_1 Mori − Tanaka_2 Mori − Tanaka_3 | Define the homogenization method used to calculate the unidirectional stiffness matrix. For further information about these methods, see [10] or [16]. |
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ClosureApproximation = Linear Quadratic HybridA HybridB ORF ORS |
Define the closure approximation method used to calculate the 4th-order orientation tensor from the 2nd-order orientation tensor given by Moldflow. For further information about these methods, see [10] or [16]. ORF calls the orthotropic fitted closure approximation proposed by [12], distinguishing between different fiber interaction coefficients based on the equation provided in [7]. ORS refers to the orthotropic smooth closure approximation. |
The following elastic constants must be defined:
| E11F = DOUBLE | Fiber Young’s modulus in main direction. |
| E22F = DOUBLE | Fiber Young’s modulus in thickness direction. |
| RHOF = DOUBLE |
Fiber density. |
| PRBAF = DOUBLE |
Fiber in-plane Poisson’s ratio. |
| PRCBF = DOUBLE |
Fiber out-of-plane Poisson’s ratio. |
| G12F = DOUBLE |
Fiber shear modulus. |
| EM = DOUBLE |
Matrix Young’s modulus. |
| RHOM = DOUBLE |
Matrix density. |
| PRM = DOUBLE |
Matrix Poisson’s ratio. |
| AspectRatio = DOUBLE |
Fiber aspect ratio (length/thickness). |
| FiberVolumeFraction = DOUBLE |
Fiber volume fraction in percent. |
| InclusionShape =
Ellipsoidal Spherical Needle Disc |
Shape of the inclusions. |
If IHIS > 3, you must define several direction-dependent curve files, representing different strain rates, so that the strain-rate and direction-dependent plasticity can be defined. The following input can be given:
| NumberOfCurveFiles = INT |
Define the number of curve files to be read. |
| CurveFileName#i = STRING |
Define the name and, if needed, path of the curve files. This card must be written NumberOfCurveFiles times. |
| NumberOfDirections = INT | Define the number of directions to which the curve files belong. The recommended value for short fiber reinforced plastic materials should be 3 |
| Direction#i = DOUBLE | Define angles, relative to the direction of flow, used to generate the plasticity curves. Typical angles are 0◦, 45◦, and 90◦. This card must be written NumberOfDirections times. |
| NumberOfStrainRates = INT | Define the number of strain rates to which the curve files belong. |
| StrainRate#i = DOUBLE | Define the strain rates that are considered by the defined curves. This card must be written NumberOfStrainRates times. |
| StrainRate#iDirection#j = INT | Define the curve IDs that belong to the respective strain-rate/direction combination. This card must be written NumberOfDirections x NumberOfStrainRates times. |