4.1
HEXAHEDRON NO.1 WITH 8 NODES
The hexahedron element
calculates deflections and stresses in space. It is a transformed element,
therefore it can have a wedging form or another oblique-angled form. The
transformation is isoparametric. The integration is carried out numerically in
all three axises according to Gauss- Legendre. Thus, the integration order can
be selected in Z88I1.TXT in
the material information lines. The order 2 is mostly sufficient. Hexahedron
No.1 is also well usable as a thick plate element, if the plate's thickness is
not too small against the other dimensions. The element causes high computing
load and needs a lot of memory, because the element stiffness matrix has the
order 24*24.
Hexahedrons No.1 can be
generated by the mesh generator Z88N from super elements Hexahedrons No.10, but Hexahedron No.1 cannot be used as a super
element.
Input:
CAD (see chapter 2.7.2):
Upper plane: 1 - 2 - 3 - 4
- 1, quit LINE function
Lower plane: 5 - 6 -7 - 8 - 5, quit LINE function
1 - 5, quit LINE function
2 - 6, quit LINE function
3 - 7, quit LINE function
4 - 8, quit LINE function
Z88I1.TXT
> KFLAG for cartesian (0) or cylindrical coordinates (1)
> IQFLAG=1 if surface and pressure loads for this element are filed in Z88I5.TXT
> 3 degrees of freedom for each node
> Element type is 1
> 8 nodes per element
> Cross-section parameter QPARA is 0 or any other value, has no influence
> Integration order INTORD for each mat info line. 2 is usually good.
Z88I3.TXT
> Integration order INTORD for stress calculation: Can be different
from INTORD in Z88I1.TXT.
0 = Calculation of stresses in the corner nodes
1,2,3,4 = Calculation of stresses in the Gauss points
> any KFLAG, has no influence
> Reduced stress flag
ISFLAG:
0 = no calculation of reduced stresses
1 = von Mises stresses in the Gauss points ( INTORD not 0 !)
Z88I5.TXT
This file is
optional and only used if in addition to nodal forces surface and pressure
loads applied onto element no.1:
> Element number with surface and pressure
load [Long]
> Pressure, positive if poiting towards the
surface [Double]
> Tangential shear, positive in local r
direction [Double]
> Tangential shear, positive in local s
direction [Double]
> 4 nodes of the loaded surface [4 x Long]
The local r direction is defined by the nodes
1-2, the local s direction is defined by the nodes 1-4. The local nodes 1, 2, 3
, 4 may differ from the local nodes 1, 2, 3, 4 used for the coincidence.
Results:
Displacements in X, Y and Z
Stresses: SIGXX, SIGYY, SIGZZ, TAUXY, TAUYZ, TAUZX, respectively for
corner nodes or Gauss points. Optional von Mises stresses.
Nodal forces in X, Y and Z for each element and each node.