Materials input data are only given as examples and should NOT be used in the design.
Input data is for shell elements only. Solid elements-specific parameters (if any) are ignored
AOPT input is not provided, as it is case-dependent.
| Parameter | Meaning | Units | Sample Input for Hexcel IM7/8552 | Comment for the chosen value |
|---|---|---|---|---|
| RO | Mass density | kg/mm3 | 1.58e-6 | |
| EA | Young's modulus - longitudinal direction; Load Curve and Tabular Data inputs are also available | MPa | 165000 | WWFE data |
| EB | Young's modulus - transverse direction; ; Load Curve and Tabular Data inputs are also available | MPa | 9000 | WWFE data |
| PRBA | Poisson's ratio ba (minor) | -- | 0.0185 | WWFE data |
| PRCA | Poisson's ratio ca (minor) - this property will not be used with 5-parameter Reissner-Mindlin shell elements (e.g. SHELL ELFORM=16); default = PRBA | -- | 0.0185 | Same as PRBA |
| PRCB | Poisson's ratio cb - this property will not be used with 5-parameter Reissner-Mindlin shell elements (e.g. SHELL ELFORM=16); default = PRBA | -- | 0.5 | WWFE data |
| TAU1 | Stress limit of the first slightly nonlinear part of the shear stress versus shear strain curve. The values TAU1 and GAMMA1 are used to define a curve of shear stress versus shear strain. These values are input if FS, defined below, is set to a value of -1.i.e. for fabrics ONLY | -- | no input | FS = 0 for unidirectional ply laminates |
| GAMMA1 | Strain limit of the first slightly nonlinear part of the shear stress versus engineering shear strain curve. | -- | no input | FS = 0 for unidirectional ply laminates |
| GAB | Shear modulus AB; Load Curve and Tabular Data inputs are also available | MPa | 5600 | WWFE data |
| GBC | Shear modulus BC | MPa | 2800 | WWFE data |
| GCA | Shear modulus CA | MPa | 5600 | Same as GAB |
| SLIMT1 | Factor to determine the minimum stress limit after stress maximum (fiber tension). Similar to *MAT_058 (MAT_054 only). | -- | 0.01 | 5% of the value recommended in description of MAT_058, as "residual" strength with the recommended value will be at the level > 128 MPa, which is too high! |
| SLIMC1 | Factor to determine the minimum stress limit after stress maximum (fiber compression). Similar to *MAT_058 (MAT_054 only). | -- | 1.0 | Following recommendation found in description of MAT_058 |
| SLIMT2 | Factor to determine the minimum stress limit after stress maximum (matrix tension). Similar to *MAT_058 (MAT_054 only).
If the 2-way fiber flag (2WAY) is set then SLIMT2 is the factor to determine the minimum stress limit after tensile failure stress is reached in the b fiber direction. |
-- | 0.1 | Following recommendation found in description of MAT_058 |
| SLIMC2 | Factor to determine the minimum stress limit after stress maximum (matrix compression). Similar to *MAT_058 (MAT_054 only).
If the 2-way fiber flag (2WAY) is set then SLIMT2 is the factor to determine the minimum stress limit after compressive failure stress is reached in the b fiber direction. |
-- | 1.0 | Following recommendation found in description of MAT_058 |
| SLIMS | Factor to determine the minimum stress limit after stress maximum (shear). Similar to *MAT_058 (MAT_054 only). | -- | 1.0 | Following recommendation found in description of MAT_058 |
| TSIZE | Time step for automatic element deletion. | s | 1e-7 | |
| ERODS | Maximum effective strain for element layer failure. A value of unity would equal 100% strain.
GT.0.0: fails when effective strain calculated assuming material is volume preserving exceeds ERODS (old way). LT.0.0: fails when effective strain calculated from the full strain tensor exceeds |ERODS|. |
mm/mm | -0.15 | |
| SOFT | Softening reduction factor for strength in crashfront elements.
It is a mathematical expedient to avoid global buckling. Physical interpretation: damage zone (delaminations and cracks) ahead of crush front |
-- | 0.57 | "Baseline" value used for MAT_054 in Ref. (page 19). |
| FS | Failure surface type:
EQ.1.0: smooth failure surface with a quadratic criterion for both the fiber (a) and transverse (b) directions. This option can be used with complete laminates and fabrics. EQ.0.0: smooth failure surface in the transverse (b) direction with a limiting value in the fiber (a) direction. This model is appropriate for unidirectional (UD) layered composites only. EQ.-1.: faceted failure surface. When the strength values are reached then damage evolves in tension and compression for both the fiber and transverse direction. Shear behavior is also considered. This option can be used with complete laminates and fabrics. |
-- | 0.0 | failure surface of a unidirectional composite-based laminate |
| EPSF | Damage initiation transverse shear strain. | mm/mm | no input (?) | |
| EPSR | Final rupture transverse shear strain. | mm/mm | no input (?) | |
| TSMD | Transverse shear maximum damage, default = 0.90. | -- | no input (?) | |
| BETA | Material angle in degrees for AOPT = 0 and AOPT = 3. BETA may be overridden on the element card, see *ELEMENT_SHELL_BETA. | deg. | ||
| E11C | Strain at longitudinal compressive strength, a-axis (positive). | mm/mm | 0.011 | WWFE data |
| E11T | Strain at longitudinal tensile strength, a-axis. | mm/mm | 0.01551 | WWFE data |
| E22C | Strain at transverse compressive strength, b-axis. | mm/mm | 0.032 | WWFE data |
| E22T | Strain at transverse tensile strength, b-axis. | mm/mm | 0.0081 | WWFE data |
| GMS | Engineering shear strain at shear strength, ab plane | mm/mm | 0.05 | WWFE data - ASTM3518 limit strain? |
| XC | Longitudinal compressive strength (positive value). |
MPa | 1590 | |
| XT | Longitudinal tensile strength, see below. | MPa | 2560 | WWFE data |
| YC | Transverse compressive strength, b-axis (positive value), see below. | MPa | 185 | WWFE data |
| YT | Transverse tensile strength, b-axis (positive value), see below. | MPa | 73 | WWFE data |
| SC | Shear strength, ab plane, see below. | MPa | 90 (5.0%) | WWFE data |
| LCXC | Load curve ID for XC vs. strain rate (XC is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | A B | A 40% increase of XC is reported at strain rates of ~120/s. [Presumably - fiber crushing instead of buckling/kinking at the microscopic level - ACh.]. However, at SR of 6/s quasi-static value is a good approximation. At automotive SRs (17-34/s) ~ 10% increase over quasi-static value should be expected (linear interpolation). |
| LCXT | Load curve ID for XT vs. strain rate (XT is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCYC | Load curve ID for YC vs. strain rate (YC is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | A | Quasi-static value of YC is a good approximation for automotive strain rates (~17-35 1/s), but must be taken into account for rates over ~100/s |
| LCYT | Load curve ID for YT vs. strain rate (YT is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCSC | Load curve ID for SC vs. strain rate (SC is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | A | Quasi-static value of SC is a good approximation for automotive strain rates (~17-35 1/s), but must be taken into account for rates over ~100/s |
| LCTAU | Load curve ID for TAU1 vs. strain rate (TAU1 is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCGAM | Load curve ID for GAMMA1 vs. strain rate (GAMMA1 is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| DT | Strain rate averaging option. EQ.0.0: Strain rate is evaluated using a running average. LT.0.0: Strain rate is evaluated using average of last 11 time steps. GT.0.0: Strain rate is averaged over the last DT time units. |
-- | no input | |
| LCE11C | Load curve ID for E11C vs. strain rate (E11C is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | A | Over 60% increase of E11C is reported at strain rates of ~120/s. However, at SR of 6/s quasi-static value is a good approximation. At automotive SRs (17-34/s) ~ 12% increase over quasi-static value should be expected (linear interpolation). |
| LCE11T | Load curve ID for E11T vs. strain rate (E11T is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCE22C | Load curve ID for E22C vs. strain rate (E22C is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCE22T | Load curve ID for E22T vs. strain rate (E22T is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCGMS | Load curve ID for GMS vs. strain rate (GMS is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |
| LCEFS | Load curve ID for ERODS vs. strain rate (ERODS is ignored with that option). If the first strain rate value in the curve is negative, it is assumed that all strain rate values are given as natural logarithm of the strain rate. | -- | no input | Strain rate sensitivity ignored dur to lack of experimental data. |