Computer Programs

NESC0775 HEMP

NESC0775 HEMP

HEMP, 2-D Elastic Plastic Flow in 2-D X-Y or Cylindrical Geometry by Lagrangian Method

NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: HEMP

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Rules for end-users are available here.

Program name	Package id	Status	Status date
HEMP	NESC0775/01	Tested	01-OCT-1980

Machines used:

Package ID	Orig. computer	Test computer
NESC0775/01	CDC 7600	CDC 7600

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3. DESCRIPTION OF PROBLEM OR FUNCTION

The  HEMP  code   solves  the
conservation equations of two-dimensional elastic-plastic flow, in
plane x-y coordinates  or in  cylindrical symmetry  around the  x-
axis.   Provisions  for  calculation  of  fixed  boundaries,  free
surfaces, pistons, and  boundary slide planes have  been included,
along with other special conditions.

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4. METHOD OF SOLUTION

The  solution  is  by the  method  of  finite
differences and  uses the  Lagrangian formulation.   The materials
within a physical  system are divided into  quadrilaterals bounded
by J  and K  grid lines.  A  decoupling of  grid lines  is allowed
along K-lines, and voids may open and close between K-lines.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The maximum number
of J's in any K-line is 101. A problem of up to about 10,000
zones may be run.

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6. TYPICAL RUNNING TIME

Basic  HEMP calculation  speed  is about  5
points (or zones)  per millisecond.  The number  of problem cycles
necessary depends on  the problem termination  time and  the time-
step size.   Typical problems  run from a  few minutes  to several
hours with time a function of  zone size, material composition and
activity in the zones.

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7. UNUSUAL FEATURES OF THE PROGRAM

The input  system, described  in
the HEMP  User's Manual is  designed so  that the least  amount of
data to  describe a particular  physical system need  be supplied.
However,  provision  is  made for  describing  initial  conditions
(zonal or nodal) in great detail, if required.

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8. RELATED AND AUXILIARY PROGRAMS:

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9. STATUS

Package ID	Status date	Status
NESC0775/01	01-OCT-1980	Tested at NEADB

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10. REFERENCES

- Mark L. Wilkins:
Calculation of Elastic Plastic Flow
UCRL-7322 Rev. 1 (January 24, 1969).

NESC0775/01, included references:

- E.D. Giroux:
HEMP User's Manual
UCRL-51079 Rev. 1 (December 17, 1973).

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11. MACHINE REQUIREMENTS

The  HEMP main  code fills  the small  core
memory (SCM) with  the code, working storage,  library, and system
routines.  The large  core memory (LCM) utilized is  a function of
problem size, the amount required is 527,270 (octal) words.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NESC0775/01	FORTRAN-IV

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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED: SCOPE 2.1.

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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Memory must be  precleared to zero.  The program treats  LCM as an
input-output storage device.  Data is accessed  to and from LCM in
K-line groups.  The dimensions of variables in LCM numbered COMMON
blocks must be adjusted for each problem.

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15. NAME AND ESTABLISHMENT OF AUTHORS

                 M. L. Wilkins and J. A. Levatin
                 Lawrence Livermore Laboratory
                 P. O. Box 808
                 Livermore, California  94550

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16. MATERIAL AVAILABLE

NESC0775/01

File name	File description	Records
NESC0775_01.001	SOURCE	14240
NESC0775_01.002	PROBLEM INPUT	29
NESC0775_01.003	PROBLEM OUTPUT	3297
NESC0775_01.004	JCL	13

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17. CATEGORIES

I. Deformation and Stress Distributions, Structural Analysis and Engineering Design Studies

Keywords: Lagrange equations, Navier-Stokes equation, elasticity, equations of state, finite difference method, fluid mechanics, hydrodynamics, plasticity, two-dimensional.