Table of Contents
RESS
Description
The RESS formulation employs just the Enhanced Assumed Strain (EAS) technique with a reduced integration scheme.
These elements have special integration schemes dedicated to analyze problems involving non-linear through-thickness distribution without requiring many element layers.
Implemented by: J.I. Velosa de Sena, December 2010
Type: 69
Prepro: RESS3A.F
Lagamine: RESS3B.F
Input file
| Title (A5) | |
|---|---|
| TITLE | 'RESS3' en colonnes 1 à 5 |
| Control data (4I5) | |
| NELEM | Number of elements |
| NEAS | Number of EAS modes (Enhanced Assumed Strain) - only available value = 1 |
| ILOAX | = 0 for global axis computation ☛ Objectivity must be verified in the material law (with Jaumann correction) ☛ No rotation of material axes |
| < 0 for computation with constant and symetrical velocity gradients pseudo local axes : use of local axes on the time step but no evolution of the local axes on the following time step ☛ Objectivity is verified ☛ No rotation of material axes |
|
| > 0 for computation with local axes ☛ Objectivity is verified ☛ Rotation of material axes |
|
| units: = 1 for rotations incorporated in local tangent matrix  Not available = 2 apply final rotation to local tangent matrix = 3 apply initial rotation to local tangent matrix = 4 compute tangent matrix through global perturbation method |
|
| tens (only for ILOAX>0): = 0 for local axes e1, e2, e3 initially parallel to global axes ex, ey, ez = 1 for local axes e1, e2 given (and e3=e1∧e2) = 2 for local axes e1, e2 initially in the plane (ex, ey) forming an angle θ with ex, ey (and e3=e1∧e2) = 3 same as 1 with different local axes for each element = 4 same as 2 with different local axes for each element |
|
| NPTH | Number of integration points on the width (in the ζ direction) of the element (NPTH ∈ [2,10]). The number of integration points in the ξ-η plane is equal to 4. |
| List of EAS modes (14I5) | |
| EAS(1) | if NEAS = 1 |
| Definition of the elements (I5/8I5) | |
| LMATE | Material law |
| NODES(8) | List of nodes |
Results
Cauchy stresses in global axes $\sigma_x,\sigma_y,\sigma_z,\sigma_{xy},\sigma_{xz},\sigma_{yz}$
Order of the integration points
Starting from negative coordinates, one varies:
- the ξ
- the η
- the ζ
Exemple for 3 IP (NPTH=3)
- ξ = 0 η = 0 ζ = -0.774
- ξ = 0 η = 0 ζ = 0
- ξ = 0 η = 0 ζ = +0.774