IAEA1181 FINEDAN.

1. NAME OR DESIGNATION OF PROGRAM:  FINEDAN.

3. DESCRIPTION OF PROGRAM OR FUNCTION

The finite elements code FINEDAN performs dynamic analysis of continua in two-dimensional Cartesian and axisymmetric geometry. Main areas of application are fast dynamic problems, involving shock or pressure wave propagation, body contact or impact problems (including penetration  problems) and sliding problems. Continua can be both fluids and solid materials. The user has the possibility to implement his own construction material models. However, basic material models related to nuclear power plants are already included in the program, such as plastic material, elastic-plastic material with isotropic and/or kinematic hardening, the CAP model for concrete, a sandwich model for reinforced concrete, the ideal gas equation, and the Murnaghan equation for liquids.

4. METHOD OF SOLUTION

For spatial discretisation, 4-node iso- parametric one-point integration elements based on the principle of  virtual work, or 4 node elements with high coarse-mesh accuracy based on multifield Hu-Washitu variational principle, were used. The latter option can be used, however, only for linear materials. The instabilities due to the hourglass modes are effectively controlled by elastic or viscous models. The shock or pressure waves are smeared out through linear or quadratic pseudoviscosities.
The equations of motion are integrated by the central difference method, which is only conditionally stable - the code uses an efficient automatic method to evaluate stable time steps for the solution. For the mass matrix, the lumped approach is used and therefore the direct solution of the equation of motion is possible  without any matrix inversion.
The code contains several methods simulating possible mechanical interactions between the elements: tied nodes; the penalty method for contact algorithm; sliding lines; and penetration algorithm with erosion limits.
The PC version enables to obtain also quasi-static solutions through the dynamic relaxation method or through the material damping method (both methods can use the mass scaling option). This  version also contains efficient control of the solution through time histories of various energies and an efficient graphical post- processor.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

This version of the  code can only solve dynamic problems involving up to:
   1000 4-node elements
   2000 nodes
    100 triangular contact elements
     50 line contact elements
    100 segments with the external given pressure
    500 tied nodes
     10 materials
     50 given functions
      5 sliding lines with 100 slave nodes.
The code has, for each element, 15 variables available so that an implementation of new material models is quite easy.
The code has no direct compatibility with any preprocessor or postprocessor.
   Dynamic allocation is provided.

6. TYPICAL RUNNING TIME

The running time depends on the number of elements used and on the number of time steps.

NEA-DB executed the test case included in the package (file INPUT.DAT) in 3 seconds on a VAX-6000  and in 4 seconds on a
66-MHz PC/80486.

7. UNUSUAL FEATURES OF THE PROGRAM

The code is convenient for the solution of impact problems. Attention was given to the modeling of  the local response of reinforced concrete structures to various impact loading. It can be applied to problems involving both fluids  and solids. It contains a penetration algorithm with erosion limits.

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES

- T. Belytschko et al:
  Hourglass control in linear and nonlinear problems. Comp. Method.
  in Appl. Mech. and Engrg., 43 (1984) 251-276.
- T. Belytschko, W.E. Bachrach:
  Efficient implementation of quadrilaterals with high coarse-mesh
accuracy. Com. Meth. in Appl. Mech. and Engrg., 54 (1986) 279-301.  - P. Matejovic:
  Quadrilateral with high coarse-mesh accuracy for solid mechanics
  in axisymmetric geometry, 10th SMIRT Conference, Anaheim,
  California, USA (1989)

- V. Adamik:
  Theoretical Manual of FINEDAN Code
  5447/RB (June 1990).
- V. Adamik:
  User's Manual of FINEDAN Code
  (December 1988).
- P. Matejovic and V. Adamik:
  A One-Point Integration Quadrilateral with Hourglass Control in
  Axisymmetric Geometry
  Reprint from Computer Methods in Applied Mechnics and Engineering
  70 (1988) 301-320.
- P. Matejovic:
  Quadrilateral with High Coarse-Mesh Accuracy for Solid Mechanics
  in Axisymmetric Geometry
  Reprint from Computer Methods in Applied Mechnics and Engineering
  88 (1991) 241-258.
- V. Adamik and P. Matejovic:
  A Contribution to Computational Modelling of Reinforced Concrete
  Structures Subjected to Impact Loadings
  Reprint from Nuclear Engineering and Design 113 (1989) 111-120.

11. MACHINE REQUIREMENTS:  PC IBM Compatible.

NEA-DB installed and executed the program both on a VAX-6000-510 computer and a DELL 466/L PC/80486 with 66 MHz and 8 MB of RAM.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  MS-DOS.

The source program was compiled both on a VAX-6000 using the FORTRAN-77 compiler and on the PC under MS-DOS 6.2 using the Lahey F77L-EM/32 Fortran 77 compiler Version 5.20 and the Microsoft Fortran compiler version 5.1.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:
The user can prepare his own models in Fortran-IV.

15. NAME AND ESTABLISHMENT OF AUTHORS

Vladislav Adamik
Nuclear Power Plants Research Institute
Okruzna 5
918 64 TRNAVA
Czech Republic.

ABAKUS a.s.
Maltezske namesti 7
118 00 PRAGUE 1
Czech Republic

File name	File description	Records
IAEA1181_01.001	This information file	122
IAEA1181_01.002	User's Manual of FINEDAN Code	0
IAEA1181_01.003	FINEDAN Fortran source code	9344
IAEA1181_01.004	Sample input used on testing	97
IAEA1181_01.005	Sample output with VAX	1584
IAEA1181_01.006	FINEDAN Fortran source code for Lahey	9355
IAEA1181_01.007	FINEDAN executable produced with Lahey	0
IAEA1181_01.008	Sample output with Lahey	1592
IAEA1181_01.009	Several inputs for FINEDAN code	1708
IAEA1181_01.010	DOS file-names	9