This is an old revision of the document!
8 node large strain volumetric element with hourglass and locking control.
Implemented by: Zhu Yongyi, January 1992
Type: 22
Prepro: BLZ3DA.F
Lagamine: BLZ3DB.F
TITLE (A5) | ||
---|---|---|
TITLE | 'BLZ3D' in columns 1 to 5 | |
CONTROL (5I5) | ||
NELEM | Number of elements | |
INDPP | =0 if no weight (or no density if NTANA=-1) | |
=1 if weight taken into account (or density) | ||
INSHE | =0 for automatic calculation of shear locking parameter | |
=1 if shear coefficient taken into account | ||
=-1 for use of element BWD3D (only 1 integration point) | ||
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 ![]() = 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 = 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 | |
= 1 for input of initial stresses | ||
CONSIDERATION OF WEIGHT (4G10.0) Only if INDPP = 1 | ||
WSPE(1) | = specific weight in X direction | |
WSPE(2) | = specific weight in Y direction | |
WSPE(3) | = specific weight in Z direction | |
WSPE(4) | = density | |
CONSIDERATION OF SHEAR LOCKING (1G10.0) Only if INSHE = 1 |
||
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) | |
INITIAL ORIENTATION OF LOCAL AXES (6G10.0) Only if tens of ILOAX = 1 or 3 | ||
e1(x) | coordinate of e1 along ex | |
e1(y) | coordinate of e1 along ey | |
e1(z) | coordinate of e1 along ez | |
e2(x) | coordinate of e2 along ex | |
e2(y) | coordinate of e2 along ey | |
e2(z) | coordinate of e2 along ez | |
Note: These vectors are normalized after reading but should be orthogonal: e1 • e2 = e1(x) * e2(x) + e1(y) * e2(y) + e1(z) * e2(z) = 0 | ||
INITIAL ORIENTATION OF LOCAL AXES (1G10.0) Only if tens of ILOAX = 2 or 4 | ||
THETA | Angle between e1 and ex in degrees | |
DEFINITION OF THE ELEMENTS (2I5/8I5/6G10) | ||
NINTE | Number of integration points (1, 2, 4 or 8) if NINTE = 1, add 40 to MVARI compared to maximum required by laws | |
LMATE | Number of the material law | |
NODES(8) | List of nodes | |
SIG0(6) | List of initial stresses (Only if ISIG0=1) |