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
Title (A5) | |
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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 |
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> 0 for computation with local axes ☛ Objectivity is verified ☛ Rotation of material axes |
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units: = 1 for rotations incorporated in local tangent matrix ![]() = 2 apply final rotation to local tangent matrix = 3 apply initial rotation to local tangent matrix = 4 compute tangent matrix through global perturbation method |
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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 |
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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 |
Cauchy stresses in global axes $\sigma_x,\sigma_y,\sigma_z,\sigma_{xy},\sigma_{xz},\sigma_{yz}$
Starting from negative coordinates, one varies:
Exemple for 3 IP (NPTH=3)