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 | MPa | 165000 | WWFE data |
| EB | Young's modulus - transverse direction | 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 |
| GAB | Shear modulus AB | MPa | 5600 | WWFE data |
| GBC | Shear modulus BC | MPa | 2800 | WWFE data |
| GCA | Shear modulus CA | MPa | 5600 | Same as GAB |
| DAF | Flag to control failure of an integration point based on longitudinal (fiber) tensile failure:
EQ.0.0: IP fails if any damage variable reaches 1.0. EQ.1.0: no failure of IP due to fiber tensile failure, da(i)=1.0 |
-- | 1.0 | |
| DKF | Flag to control failure of an integration point based on longitudinal (fiber) compressive failure:
EQ.0.0: IP fails if any damage variable reaches 1.0. EQ.1.0: no failure of IP due to fiber compressive failure, dkink(i)=1.0 |
-- | 1.0 | |
| DMF | Flag to control failure of an integration point based on transverse (matrix) failure:
EQ.0.0: IP fails if any damage variable reaches 1.0. EQ.1.0: no failure of IP due to fiber compressive failure, dkink(i)=1.0 |
-- | 1.0 | |
| EPS | 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 EFS. LT.0.0: fails when effective strain calculated from the full strain tensor exceeds |EFS|. |
mm/mm | 0.15 | |
| GXC | Fracture toughness for longitudinal (fiber) compressive failure mode.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GXC) which defines the fracture toughness for fiber compressive failure mode as a function of characteristic element length. No further regularization. |
N/mm | 79.9 | Due to the lack of experimental data specific to IM7/8552, assumed the same as measured experimentally in Ref. for T300/1034-C composite |
| GXT | Fracture toughness for longitudinal (fiber) tensile failure mode.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GXT) which defines the fracture toughness for fiber tensile failure mode as a function of characteristic element length. No further regularization. |
N/mm | 91.6 | Due to the lack of experimental data specific to IM7/8552, assumed the same as measured experimentally in Ref. for T300/1034-C composite |
| GYC | Fracture toughness for transverse (fiber) compressive failure mode.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GYC) which defines the fracture toughness for transverse compressive failure mode as a function of characteristic element length. No further regularization. |
N/mm | 0.76 | Due to the lack of experimental data specific to IM7/8552, assumed the same as provided in Ref. for T300/1034-C composite |
| GYT | Fracture toughness for transverse (fiber) tensile failure mode.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GYT) which defines the fracture toughness for transverse tensile failure mode as a function of characteristic element length. No further regularization. |
N/mm | 0.2 | This parameter is equivalent to G_Ic obtained from DCB experiments. |
| GSL | Fracture toughness for in-plane shear failure mode.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GSL) which defines the fracture toughness for in-plane shear failure mode as a function of characteristic element length. No further regularization. |
N/mm | 0.8 | This parameter is equivalent to G_IIc obtained from ENF experiments. |
| GXCO | Fracture toughness for longitudinal (fiber) compressive failure mode to define bi-linear damage evolution.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GXCO) which defines the fracture toughness for fiber compressive failure mode to define bi-linear damage evolution as a function of characteristic element length. No further regularization. |
N/mm | 7.99 | Assuming that GXCO = 0.1 x GXC |
| GXTO | Fracture toughness for longitudinal (fiber) tensile failure mode to define bi-linear damage evolution.
GT.0.0: The given value will be regularized with the characteristic element length. LT.0.0: Load curve ID = (-GXTO) which defines the fracture toughness for fiber tensile failure mode to define bi-linear damage evolution as a function of characteristic element length. No further regularization. |
N/mm | 9.16 | Assuming that GXTO = 0.1 x GXT |
| XC | Longitudinal compressive strength, a-axis (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-XC) which defines the longitudinal compressive strength vs. longitudinal strain rate. |
MPa | 1590 | WWFE data |
| XT | Longitudinal tensile strength, a-axis (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-XT) which defines the longitudinal tensile strength vs. longitudinal strain rate. |
MPa | 2560 | WWFE data |
| YC | Transverse compressive strength, b-axis (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-YC) which defines the transverse compressive strength vs. transverse strain rate. |
MPa | 185 | WWFE data |
| YT | Transverse tensile strength, b-axis (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-YT) which defines the transverse tensile strength vs. transverse strain rate. |
MPa | 73 | WWFE data |
| SL | Shear strength, ab plane.
GT.0.0: constant value LT.0.0: Load curve ID = (-SL) which defines the in-plane shear strength vs. in-plane strain rate. |
MPa | 90 (5.0%) | WWFE data |
| XCO | Longitudinal compressive strength at inflection point (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-XCO) which defines the longitudinal compressive strength at inflection points vs. longitudinal strain rate. |
MPa | 79.5 | Assuming that XCO = 0.05 x XC (i.e. 5% XC) |
| XTO | Longitudinal tensile strength at inflection point (positive value).
GT.0.0: constant value LT.0.0: Load curve ID = (-XTO) which defines the longitudinal tensile strength at inflection points vs. longitudinal strain rate. |
MPa | 128 | Assuming that XTO = 0.05 x XT (i.e. 5% XT) |
| FIO | Fracture angle in pure transverse compression (in degrees, default = 53.0). | Deg. | 53.0 | Default value |
| SIGY | In-plane shear yield stress.
GT.0.0: constant value LT.0.0: Load curve ID = (-SIGY) which defines the in-plane shear yield stress vs. in-plane shear strain rate. |
MPa | 60 (1%) | |
| ETAN | Tangent modulus for in-plane shear plasticity.
GT.0.0: constant value LT.0.0: Load curve ID = (-ETAN) which defines the tangent modulus vs. in-plane shear strain rate. |
MPa | 750 | Determined from Fig. 1 in Ref. |
| BETA | Hardening parameter for in-plane shear plasticity (0.0 ≤ BETA ≤1.0).
EQ.0.0: Pure kinematic hardening EQ.1.0: Pure isotropic hardening 0.0 < BETA < 1.0: mixed hardening. |
-- | 0.0 | |
| PFL | Percentage of layers which must fail until crashfront is initiated. E.g. |PFL| = 80.0, then 80% of layers must fail until strengths are reduced in neighboring elements. Default: all layers must fail. A single layer fails if 1 in-plane IP fails (PFL > 0) or if 4 in-plane IPs fail (PFL < 0). | 100 | Default value | |
| PUCK | Flag for evaluation and post-processing of Puck’s inter-fiber-failure criterion (IFF, see Puck, Kopp and Knops [2002]).
EQ.0.0: no evaluation of Puck’s IFF-criterion. EQ.1.0: Puck’s IFF-criterion will be evaluated |
-- | 1.0 | |
| SOFT | Softening reduction factor for material strength in crashfront elements (default = 1.0). TFAIL must be greater than zero to activate this option. Crashfront elements are elements that are direct neighbors of failed (deleted) 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 in Ref. (page 19). |
| 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 |