last modified: 24-JUN-1991 | catalog | categories | new | search |

NESC1120 SAMCR.

SAMCR, 2-D Elastodynamic Fracture Analysis

top ]
1. NAME OR DESIGNATION OF PROGRAM:  SAMCR.
top ]
2. COMPUTERS
To submit a request, click below on the link of the version you wish to order. Only liaison officers are authorised to submit online requests. Rules for requesters are available here.
Program name Package id Status Status date
SAMCR NESC1120/01 Tested 24-JUN-1991

Machines used:

Package ID Orig. computer Test computer
NESC1120/01 UNIVAC 1100 CDC CYBER 830
top ]
3. DESCRIPTION OF PROGRAM OR FUNCTION

SAMCR is a two-dimensional, elastodynamic, finite element code for the stress analysis of moving cracks. The code can be used to provide useful information about the Mode I fracture behavior of bodies under a combination of mechanical, thermal, and pressure loadings for materials that permit a linear-elastic fracture mechanics assumption. Major features of SAMCR are: efficient explicit finite element formulation based on four-node isoparametric quadrilateral elements; crack advance calculations based on a crack tip restraining force model; J-integral formulation for calculation of the dynamic stress intensity factor K; flexibility in the specification of the crack tip velocity versus K fracture constitutive relationship; thermal effects, both for thermal strains and for the crack tip velocity versus K constitutive relationship; energy calculations (strain, fracture, kinetic, and dissipated/damping) as a monitor of solution  accuracy; automatic time step selection; "static" analysis using dynamic relaxation; and an analysis restart options.
The code has been shown to perform well in modelling dynamic behavior of both uncracked and cracked structures and has been demonstrated to provide useful information regarding run-arrest events in polymeric laboratory samples and large thermally shocked steel cylinders.
A graphics postprocessor, TEKPLOTS, is included which using data from SAMCR output files can generate the following plots: stress intensity factor versus time or crack tip location, crack tip location versus time, crack tip velocity versus time or crack tip location, energy components versus time, nodal displacements versus  time, nodal accelerations versus time, and element strains versus time or normalized crack tip location.
top ]
4. METHOD OF SOLUTION

The mathematical formulation is based on the conventional variational formulation of finite element theory using  the principle of virtual works. Four-noded quadrilateral isoparametric elements are used together with explicit time integration and a restraining nodal force model of incremental crack advance. The code operates in a predictive fracture "application" mode, i.e., the increment of crack extension at each time step is automatically computed based on the calculated stress intensity value K at the crack tip and the user-specified crack tip velocity versus constitutive relationship for the fracturing material.
top ]
5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:
top ]
6. TYPICAL RUNNING TIME

NESC executed the sample problem in less than 4 CP minutes on the UNIVAC1100/62.
NESC1120/01
At NEADB the test case was executed on a CDC CYBER830 computer in 128 seconds of CPU time.
top ]
7. UNUSUAL FEATURES OF THE PROGRAM:
top ]
8. RELATED AND AUXILIARY PROGRAMS

A preliminary version of SAMCR was  developed by J. M. Etheridge of the Naval Surface Weapons Center. The dynamic calculations in SAMCR require specification of the initial nodal displacements and velocities, which can be computed using a conventional static finite element code. The DOASIS program  from Weiler Research, Inc. was used at the University of Maryland.
top ]
9. STATUS
Package ID Status date Status
NESC1120/01 24-JUN-1991 Tested at NEADB
top ]
10. REFERENCES

- SAMCR, NESC No. 1120, SAMCR Tape Description
  NESC Note 89-98 (September 29, 1989).
NESC1120/01, included references:
- C.W. Schwartz et al.:
  SAMCR - A Two-Dimensional Dynamic Finite Element Code for the
  Stress Analysis of Moving CRacks
  NUREG/CR-3891 (ORNL/Sub/79-7778/3) (November 1984).
- C.W. Schwartz:
  Usage Notes for Program "TEKPLOTS"
  University of Maryland Memorandum (May 1988).
top ]
11. MACHINE REQUIREMENTS

68,000 words of memory are required for execution. TEKPLOTS requires a Tektronix 401x graphics terminal for  generating the graphics displays.
NESC1120/01
To run the test case on a CDC CYBER 830 computer, 226,300 (octal) words of main storage are required.
top ]
12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NESC1120/01 FORTRAN-V (UNIVAC)
top ]
13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  EXEC 1100.
NESC1120/01
The program ran at NEADB on CDC CYBER 830 under NOS2.5.1.
top ]
14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

TEKPLOTS uses the proprietary Tektronix PLOT10 and Advanced Graphing 2 libraries; these libraries are not included.
top ]
15. NAME AND ESTABLISHMENT OF AUTHORS

         C.W. Schwartz
         Department of Civil Engineering
         University of Maryland
top ]
16. MATERIAL AVAILABLE
NESC1120/01
File name File description Records
NESC1120_01.001 Information file 53
NESC1120_01.002 Control information (author) 134
NESC1120_01.003 JCL and contol information (NEADB) 39
NESC1120_01.004 SAMCR FORTRAN source for UNIVAC 1100(author) 2611
NESC1120_01.005 SAMCR FORTRAN source (NEADB) 2624
NESC1120_01.006 SAMCR sample problerm input 1949
NESC1120_01.007 TEKPLOTS FORTRAN source UNIVAC 1100 (author) 1773
NESC1120_01.008 TEKPLOTS FORTRAN source (NEADB) 1761
NESC1120_01.009 SAMCR sample problem output 3564
top ]
17. CATEGORIES
  • I. Deformation and Stress Distributions, Structural Analysis and Engineering Design Studies

Keywords: finite element method, strains, stress analysis, two-dimensional.