This section describes the options available for the mapping of material properties for *MAT_ANISOTROPIC_ELASTIC_PLASTIC (*MAT_157). The initial input is the same as above, with minor changes to the target options and additional cards specific for the initialization of material properties for (*MAT_157) with the *INITIAL_STRESS_SOLID card. You must choose which history variables should be initialized through the Envyo application.
This section covers:
| TargetMaterialModel = 157 |
Specify the target material model used in the subsequent analysis, if not initializing with *ELEMENT_SHELL_COMPOSITE. Options are 157 or 215 referring to respective material model IDs in the LS-DYNA application’s material model manual [20]. |
| 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. |
| 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). |
| 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 perpendicular to the main 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. |