NESC0975 INGEN.

1. NAME OR DESIGNATION OF PROGRAM:  INGEN.

3. DESCRIPTION OF PROBLEM OR FUNCTION

INGEN is a general-purpose mesh generator for use in conjunction with two- and three-dimensional finite element programs. The basic components of INGEN are surface and three-dimensional region generators that use linear-blending interpolation formulae. These generators are based on an i, j, k index scheme, which is used to number nodal points, construct elements, and develop displacement and traction boundary conditions.

4. METHOD OF SOLUTION

The user of INGEN develops a mesh grading by first generating the boundary edges of the mesh with the desired spacing of nodal points using the line and circular-arc generators and then using surface and volume (three-dimensional region) genera- tors, both of which preserve this spacing. The surface nodal-point generator preserves this spacing by using the nodal points as they are distributed along the boundary edges as the criteria for spacing the surface nodal points. Similary, the volume nodal-point generator calculates the interior nodal points, using the surface nodal points as the criteria for spacing the interior nodal points. Both the sur- face and volume generators use linear-blending interpolation equa- tions for calculating nodal point coordinates.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The origin cannot be used as the coordinates of a nodal point because the zero coordi- nates are a test used for nonexistent nodal points.

6. TYPICAL RUNNING TIME

Compilation (OPT=2) and execution of the sample problems requires approximately 31 CPU seconds on a CDC7600.

The test case included in this package was executed on  a CDC CYBER 830 computer in 151 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM

An INGEN program option allows the user to change (i.e., expand or contract) a mesh without altering all of the input data. It is also possible to use contraction for some portions of the mesh and expansion for other portions.

8. RELATED AND AUXILIARY PROGRAMS

Early editions of the program were  developed at Thiokol Corporation, Wasatch Division. INGEN provides input compatible with the NONSAP-C (NESC Abstract 974) and ADINA programs. SLIC (NESC Abstract 968) and QMESH (NESC Abstract 612) also generate meshes for use with finite element programs.

10. REFERENCES

- W.A. Cook,
  INGEN: A General-Purpose Mesh Generator for Finite-Element Codes,
  LA-9402-MS, June 1982.
- C.A. Anderson, P.D. Smith, and L.M. Carruthers,
  NONSAP-C: A Nonlinear Stress Analysis Program for Concrete Con-
  tainments Under Static, Dynamic, and Long-Term Loadings,
  NUREG/CR-0416 (LA-7496-MS Rev.1), January 1982.
- K.J. Bathe, E.L. Wilson, and R.H. Iding,
  NONSAP: A Structural Analysis Program for Static and Dynamic Res-
  ponse of Nonlinear Systems,
  UC-SESM-74-3, February 1974.
- K.J. Bathe,
  ADINA, A Finite Element Program for Automatic Dynamic Incremental
  Nonlinear Analysis,
  Massachusetts Institute of Technology Report 82448-1, September
  1975, revised May 1977.

- W.A. Cook :
  INGEN: A General-Purpose Mesh Generator for Finite-Element Codes
  LA-9402-MS (June 1982)

11. MACHINE REQUIREMENTS

INGEN requires approximately 137,000 (octal)  words of small core memory and 354K (octal) words of large core memory for CDC7600 execution.

155,216 (octal) word (CM); 353,740 (octal) words (LCM).

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

NOS2.5.1 (CDC CYBER 830).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Use of  the CDC FTN compiler options, ROUND and OPT=2 is recommended.

15. NAME AND ESTABLISHMENT OF AUTHOR

W.A. Cook
Los Alamos National Laboratory
P.O. Box 1663
Los Alamos, New Mexico 87545

File name	File description	Records
NESC0975_01.001	Information file	45
NESC0975_01.002	JCL and control information	8
NESC0975_01.003	INGEN FORTRAN source	4234
NESC0975_01.004	Sample problem input	1191
NESC0975_01.005	Sample problem output	9782