Table of Contents
BEM3D
3D boundary element
Description
Boundary element using the “BEM” method in linear elastic mechanical analysis.
A group of BEM boundary elements defines a region considered as an equivalent finite element.
No volumetric force is taken into account.
Type: 61
Implemented by: Y.S. Jiang, 1991
Files
Prepro: BE3DIM.F, BEM3DA.F
Lagamine: BEM3DB.F
Input file
| Title (A4) | |
|---|---|
| TITLE | “BEM3D” in the first 5 columns |
| Control data (I5) | |
| NEFEQ | Number of equivalent finite elements |
| NX | = 1 if the problem is symmetrical with respect to a plane perpendicular to axis X = 0 else |
| NY | = 1 if the problem is symmetrical with respect to a plane perpendicular to axis Y = 0 else |
| NZ | = 1 if the problem is symmetrical with respect to a plane perpendicular to axis Z (not available yet) = 0 else |
| X | Coordinate of the symmetry plane along X |
| Y | Coordinate of the symmetry plane along Y |
| Z | Coordinate of the symmetry plane along Z |
Definition of an equivalent finite element
This section must be repeated NEFEQ times.
| Control data (9I5) | |
|---|---|
| LMATE | Material law - only the elastic material is accessible |
| NSUBE | Number of boundary BEM elements |
| NSUBD | Total number of nodes taken into account in the boundary elements |
| NSIGP | Number of interior points where stresses should be computed |
| NORET | Index for rigid body rotation ( Not available) |
| NTRAC | Number of surface traction ( Not available) |
| IFTRA | Index for the calculation of nodal traction at each step ( Not available): = 1 Yes ≠ 1 No |
| NRI | Index for the control of rigid body rotation ( Not available) |
| INSOL | Index for the choice of fundamental solution ( Not available): = 1 Green (fluid mechanics, problem of potential) = 2 Kelvin (solid mechanics) = 2 Mindlin (solid mechanics) |
| NINF | Index for the type of domain: = 0 Finite domain = 1 Infinite domain |
| Definition of the BEM elements (2I5/NELND(I5)) - Repeated NSUBE times | |
| NELND | Number of nodes of the boundary element (3, 4, 6 or 8) |
| NINP | Number of Gauss integration points (1, 4, or 9) |
| NODE(I) I=1,NELND | List of nodes of the BEM element |
| Definition of the points of stress computation 3G10.0) - repeated NSIGP times | |
| XP | Coordinates of the point where the stress must be computed |
| YP | |
| ZP | |
Remarks
4 types of boundary elements are available:
The numbering direction must be done in order to get a normal to the element surface directed outwards of the domain.