MATF

Format

Example

Definitions

Comments

1. MID field may refer to MAT1, MAT2, MAT8, MAT9 or MAT9ORT entries.
2. For laminated shells (PCOMP/PCOMPP/PCOMPG).
   V1, V2, through V5 specify material stress limits.

   V1

   Tensile stress limit in longitudinal direction

   V2

   Compressive stress limit in longitudinal direction

   V3

   Tensile stress limit in lateral direction

   V4

   Compressive stress limit in lateral direction

   V5

   In-plane shear stress limit

   For Solid Elements (MAT9/MAT9OR) and Continuum Shells (PCOMPLS).

   V1, V2 through V9 specify material stress limits.

   V1

   Tensile stress limit in 1-1 direction

   V2

   Compressive stress limit in 1-1 direction

   V3

   Tensile stress limit in 2-2 direction

   V4

   Compressive stress limit in 2-2 direction

   V5

   Tensile stress limit in 3-3 direction

   V6

   Compressive stress limit in 3-3 direction

   V7

   Shear stress limit in 1-2 direction

   V8

   Shear stress limit in 2-3 direction

   V9

   Shear stress limit in 1-3 direction

   Coordinate system 1-2-3 are user-defined for continuum shell elements or solid elements with MAT9.

3. W1, W2 and W3 definition is dependent on the failure criterion specified.
   • PUCK/PUCK3D specify failure envelope parameters:

     W1

     Failure envelope factor 12(-)

     W2

     Failure envelope factor 12(+)

     If W2 is blank, it is set to be equal to W1, W1 and W3 should be specified.

     W3

     Failure envelope factor 22(-)

   • TSAI3D on anisotropic solid material

     They are the tensile stress limits in equal-biaxial tension tests. W1 is the tensile stress limit in equal-biaxial tests where the two tensile loads are in directions 1 and 2. W1 is mandatory, while W2 and W3 are optional. If W2 and W3 are not specified, then they are set equal to W1. The definition of W2 and W3 is similar to W1. W2 is the tensile stress limit in equal-biaxial tension tests where the two tensile loads are in directions 2 and 3. W3 is the tensile stress limit in equal-biaxial tension tests where the two tensile loads are in directions 1 and 3.

   • HASH3D

     When Hashin failure criteria is applied on continuum shell elements, W1 is defined as alpha, which takes the transverse shear stress (in 1-2 and 1-3 direction) into account in the tensile fiber check. When W1 is blank, alpha is assumed to be 1.0.

   • CNTZ3D
     When using Cuntze failure criterion, W1, W2, and W3, corresponding to the three free curve parameters, $b_{\perp \left|\right|}$ , $b_{\perp }^T$ and $b_{\perp \left|\right|}^{\tau }$ should be provided. The free curve parameters can be determined from multi-axial test data from experiments. Bounds on the safe side for GFRP, CFRP and AFRP are assumed by Cuntze ¹ to be:(1)

     $$\mathrm{0.0.5}<b_{\perp \left|\right|}<0.15,1.0<b_{\perp |}^T<1.6,0<b_{\perp \left|\right|}^{\tau }<0.4$$
4. Different failure criteria for different materials can be defined by referencing the corresponding material entry (with same ID as MATF) on MID# fields of the PCOMP and PLY entries (for PCOMPP). If different materials with different failure criteria are required to be defined for a single composite property, then MATF entry should be used.
5. The following criteria can only be defined on the MATF entry.

   PUCK, DUCTILE, PUCK3D, HILL3D, HOFF3D, TSAI3D, HASH3D, STRN3D, and CNTZ3D.

   The rest of the criteria can also be defined on the FT field of the corresponding PCOMPP/PCOMPG/PCOMP entry.

   For the PUCK failure criterion, even though it is available on the FT field of the PCOMPP/PCOMPG/PCOMP entry, the corresponding failure envelope factors (W1, W2, W3) can only be defined on the MATF entry. Therefore, the MATF entry is mandatory when PUCK failure criterion is requested via the FT field of PCOMP/PCOMPG/PCOMPP entries, and additionally, the allowables should be defined on the MATF for PUCK criterion only. To use PUCK failure criteria, the MATF entry should be specified with MID referring to the corresponding material entry.

6. If the CRITERIA field is set to DUCTILE, then the TID field should point to a TABLEMD entry with NDEP set to 1. The first data column (Yi) is the equivalent plastic strain at the onset of damage. The second data column (Xi) is the corresponding temperature. The second column should be specified in ascending order only.

   When the CRITERIA field is set to DUCTILE in OSTTS analysis, the temperature-based lookup is conducted for each temperature to identify the corresponding equivalent plastic strain from the TABLEMD entry. This plastic strain is used in conjunction with the calculated von Mises Strain to calculate Damage (This can be output using the DAMAGE I/O Options Entry).