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 net 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
> KFLAG for cartesian (0) or cylindrical coordinates (1)
> 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.
> 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 !)
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.