elements:ssh3d
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elements:ssh3d [2020/08/25 15:46] (current) |
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| ====== SSH3D ====== | ====== SSH3D ====== | ||
| + | 3D solid-shell element | ||
| ===== Description ===== | ===== Description ===== | ||
| + | {{ :elements:blz3d.png?300|}} | ||
| + | Type: 23 \\ \\ | ||
| + | Implemented by: A. Ben Bettaieb, L. Duchêne, A-M. Habraken (2009) | ||
| - | {{ :elements:blz3d.png?300|}} | + | ==== Files ==== |
| - | The SSH3D formulation employs the | + | |
| - | Enhanced Assumed Strain (EAS) technique based on the Hu-Washizu variational principle combined with the Assumed Natural Strain (ANS) technique in order to overcome various locking pathologies. \\ | + | |
| - | + | ||
| - | Implemented by: Amine Ben Bettaieb, December 2009 | + | |
| - | + | ||
| - | Type: 23 | + | |
| Prepro: SSH3DA.F \\ | Prepro: SSH3DA.F \\ | ||
| - | Lagamine: SSH3DB.F\\ | + | Lagamine: SSH3DB.F |
| ===== Input file ===== | ===== Input file ===== | ||
| - | ^TITLE (A5)^^ | + | ^Title (A5)^^ |
| - | |TITLE | 'SSH3D' en colonnes 1 à 5| | + | |TITLE|"SSH3D" in the first 5 columns| |
| - | ^CONTROL (4I5)^^ | + | ^Control data (4I5)^^ |
| - | |NELEM | Nombre d'éléments | | + | |NELEM|Number of elements| |
| - | |NEAS | Nombre de modes EAS (Enhanced Assumed Strain) compris entre 1 et 30 | | + | |NEAS|Number of EAS modes (Enhanced Assumed Strain), between 1 and 30| |
| - | |ILOAX | Calcul avec les axes locaux| | + | |ILOAX |= 0 for global axis computation \\ ☛ Objectivity must be verified in the material law (with Jaumann correction)\\ ☛ No rotation of material axes| |
| - | |::: |=1 if shear coefficient taken into account| | + | |:::|< 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| |
| - | |::: |=-1 for use of element BWD3D (only 1 integration point)| | + | |:::|> 0 for computation with local axes \\ ☛ Objectivity is verified \\ ☛ Rotation of material axes| |
| - | |ILOAX |=0 for global axis computation \\ ☛ Objectivity must be verified in the material law \\ ☛ 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| | |:::|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 e<sub>1</sub>, e<sub>2</sub>, e<sub>3</sub> initially parallel to global axes e<sub>x</sub>, e<sub>y</sub>, e<sub>z</sub> \\ = 1 for local axes e<sub>1</sub>, e<sub>2</sub> given (and e<sub>3</sub>=e<sub>1</sub>∧e<sub>2</sub>) \\ = 2 for local axes e<sub>1</sub>, e<sub>2</sub> initially in the plane (e<sub>x</sub>, e<sub>y</sub>) forming an angle θ with e<sub>x</sub>, e<sub>y</sub> \\ = 3 same as 1 with different local axes for each element \\ = 4 same as 2 with different local axes for each element| | + | |:::|tens (only for ILOAX>0): \\ = 0 for local axes e<sub>1</sub>, e<sub>2</sub>, e<sub>3</sub> initially parallel to global axes e<sub>x</sub>, e<sub>y</sub>, e<sub>z</sub> \\ = 1 for local axes e<sub>1</sub>, e<sub>2</sub> given (and e<sub>3</sub>=e<sub>1</sub>∧e<sub>2</sub>) \\ = 2 for local axes e<sub>1</sub>, e<sub>2</sub> initially in the plane (e<sub>x</sub>, e<sub>y</sub>) forming an angle θ with e<sub>x</sub>, e<sub>y</sub> (and e<sub>3</sub>=e<sub>1</sub>∧e<sub>2</sub>)\\ = 3 same as 1 with different local axes for each element \\ = 4 same as 2 with different local axes for each element| |
| - | |ISIG0| = 0 if no initial stresses| | + | |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.| |
| - | |:::| = 1 for input of initial stresses| | + | ^1 to 3 lines depending on NEAS value - List of EAS modes (14I5)^^ |
| - | ^CONSIDERATION OF WEIGHT (4G10.0) \\ Only if INDPP = 1 ^^ | + | |EAS(List1)|List of 1:NEAS if NEAS ∈ [1,14] or 1:14 if NEAS > 14| |
| - | |WSPE(1)| = specific weight in X direction| | + | |EAS(List2)|List of 15:NEAS if NEAS ∈ [15,28] or 15:28 if NEAS > 28| |
| - | |WSPE(2)| = specific weight in Y direction| | + | |EAS(List3)|List of 29:NEAS if NEAS ∈ [29,30]| |
| - | |WSPE(3)| = specific weight in Z direction| | + | ^Definition of the elements (I5/8I5)^^ |
| - | |WSPE(4)| = density| | + | |LMATE|Material law| |
| - | ^CONSIDERATION OF SHEAR LOCKING (1G10.0) \\ Only if INSHE = 1 ^^ | + | |NODES(8)|List of nodes| |
| - | |PARSHE| Shear locking coefficient ∈ [0,1] \\ - close to 0: avoid shear locking but higher risk of hourglass modes (use for thin elements in flexion) \\ - close to 1: avoid hourglass modes but higher risk of shear locking (use for cubic elements in shear)| | + | ===== Results ===== |
| - | ^INITIAL ORIENTATION OF LOCAL AXES (6G10.0) \\ Only if tens of ILOAX = 1 or 3^^ | + | Cauchy stresses in global axes $\sigma_x,\sigma_y,\sigma_z,\sigma_{xy},\sigma_{xz},\sigma_{yz}$ |
| - | |e<sub>1</sub>(x)|coordinate of e<sub>1</sub> along e<sub>x</sub>| | + | |
| - | |e<sub>1</sub>(y)|coordinate of e<sub>1</sub> along e<sub>y</sub>| | + | ===== Order of the integration points ===== |
| - | |e<sub>1</sub>(z)|coordinate of e<sub>1</sub> along e<sub>z</sub>| | + | Starting from negative coordinates, one varies: \\ |
| - | |e<sub>2</sub>(x)|coordinate of e<sub>2</sub> along e<sub>x</sub>| | + | - the ξ |
| - | |e<sub>2</sub>(y)|coordinate of e<sub>2</sub> along e<sub>y</sub>| | + | - the η |
| - | |e<sub>2</sub>(z)|coordinate of e<sub>2</sub> along e<sub>z</sub>| | + | - the ζ |
| - | |Note: These vectors are normalized after reading but should be orthogonal: \\ e<sub>1</sub> • e<sub>2</sub> = e<sub>1</sub>(x) * e<sub>2</sub>(x) + e<sub>1</sub>(y) * e<sub>2</sub>(y) + e<sub>1</sub>(z) * e<sub>2</sub>(z) = 0|| | + | Example for 8 IP: |
| - | ^INITIAL ORIENTATION OF LOCAL AXES (1G10.0) \\ Only if tens of ILOAX = 2 or 4^^ | + | - ξ = -0,57; η = -0,57; ζ = -0,57 |
| - | |THETA| Angle between e<sub>1</sub> and e<sub>x</sub> in degrees| | + | - ξ = -0,57; η = -0,57; ζ = +0,57 |
| - | ^DEFINITION OF THE ELEMENTS (2I5/8I5/6G10)^^ | + | - ξ = -0,57; η = +0,57; ζ = -0,57 |
| - | |NINTE| Number of integration points (1, 2, 4 or 8) \\ if NINTE = 1, add 40 to MVARI compared to maximum required by laws | | + | - ξ = -0,57; η = +0,57; ζ = +0,57 |
| - | |LMATE| Number of the material law| | + | - ξ = +0,57; η = -0,57; ζ = -0,57 |
| - | |NODES(8)| List of nodes| | + | - ξ = +0,57; η = -0,57; ζ = +0,57 |
| - | |SIG0(6)| List of initial stresses (Only if ISIG0=1)| | + | - ξ = +0,57; η = +0,57; ζ = -0,57 |
| + | - ξ = +0,57; η = +0,57; ζ = +0,57 | ||
elements/ssh3d.1553618267.txt.gz · Last modified: 2020/08/25 15:34 (external edit)
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