Shell Element Anisotropic Material Property Definition
Description: Defines the material properties for linear, temperature-independent, anisotropic materials for isoparametric shell elements.
Format:
Example:
| Field | Definition | Type | Default |
|---|---|---|---|
| MID | Material identification number. | Integer > 0 | Required |
| Gij | The material property matrix. | Real | Required |
| RHO | Mass density. | Real or blank | 0.0 |
| Ai | Thermal expansion coefficient vector. | Real or blank | 0.0 |
| TREF | Reference temperature for the calculation of thermal loads. | Real or blank | 0.0 |
| GE | Structural element damping coefficient. See Remarks 8, 9, and 11. | Real or blank | 0.0 |
| ST, SC, SS | Allowable stresses in tension, compression, and shear, respectively. Required if composite element failure index is desired. | Real or blank | 0.0 |
| CS | Honeycomb sandwich core cell size. Required if material defines the core of a honeycomb sandwich and dimpling stability index is desired (LAM = HCS on the PCOMP entry). | Real ≥ 0.0 or blank | 0.0 |
| EC | Honeycomb sandwich core Young's modulus used for stability index analysis. | Real ≥ 0.0 or blank | E |
| GC | Honeycomb sandwich core shear modulus used for stability index analysis. | Real ≥ 0.0 or blank | G |
| ALPHA0 | Fracture angle for uniaxial transverse compression in degrees. Used in the NASA LaRC02 failure theory only (see LARC02 in PCOMP entry). See Remark 12. | 0.0 ≤ Real ≤ 90.0 | 53.0 |
Remarks:
- The material identification number must be unique for all MATi entries.
- The convention for the Gij in fields 3 through 8 are represented by the matrix relationship:
- If this entry is referenced by the MID3 field (transverse shear) on the PSHELL, then G13, G23, and G33 must be blank.
- Unlike the MAT1 entry, data from the MAT2 entry is used directly, without adjustment of equivalent E, G, or NU values.
- MAT2 materials may be made temperature-dependent by use of the MATT2 entry. In STATIC solutions, linear elastic material properties will be updated as prescribed under the TEMPERATURE Case Control command.
- The mass density, RHO, will be used to automatically compute mass for all structural elements.
- Weight density may be used in field 9 if the value 1/g is entered on the PARAM, WTMASS entry, where g is the acceleration of gravity.
- To obtain the damping coefficient GE, multiply the critical damping ratio C/C0, by 2.0.
- TREF and GE are ignored if the MAT2 entry is referenced by a PCOMP entry.
- TREF is used only as the reference temperature for the calculation of thermal loads in linear solutions. If TEMPERATURE(INITIAL) is specified, TREF will be ignored.
- If PARAM, W4 is not specified, GE is ignored in transient response analysis. (See Section 5, Parameters, for more information on W4.)
- The default value for ALPHA0 has been found experimentally and is typical for fiber reinforced polymer laminates.