last modified: 01-NOV-1975 | catalog | categories | new | search |

NESC0581 SLADE-D

SLADE-D, Transient Dynamic Response of Elastic Shells by Finite Elements Method

top ]
1. NAME OR DESIGNATION OF PROGRAM:  SLADE-D
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
SLADE-D NESC0581/01 Tested 01-NOV-1975

Machines used:

Package ID Orig. computer Test computer
NESC0581/01 IBM 370 series IBM 370 series
top ]
3. DESCRIPTION OF PROBLEM OR FUNCTION

SLADE-D analyzes the transient  dynamic response of elastic shells.
top ]
4. METHOD OF SOLUTION

SLADE-D uses the finite-element method in space and central-difference scheme in time.
top ]
5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:  Maxima of -, 650 elements, 700 nodal points
top ]
6. TYPICAL RUNNING TIME

Running time is controlled by the size of the mesh and the length in time for which the response is sought.
top ]
7. UNUSUAL FEATURES OF THE PROGRAM

SLADE-D is designed for the dynamic analysis of thin shells. A doubly-curved, arbitrary quadrilateral element is utilized. The element is based on a minimum potential energy principle for thin shells. A simple central- difference time integration scheme together with a diagonal mass matrix is used to compute the transient dynamic response. Since the  majority of aerospace structures are based on shells of revolution,  the program is designed specifically for a shell the reference surface of which is a portion of an axisymmetric surface. The program allows up to five separate layers and up to five separate elastic anisotropic materials with temperature-dependent properties. SLADE-D handles variable-thickness shells and allows thickness discontinuities along element boundaries. It provides for both normal and tangential surface loads and for temperature changes through the thickness as well as varying temperatures over the reference surface. Over any portion of the boundary, a choice of thirteen separate boundary conditions is available. To ease data preparation, simple but effective generation schemes are built into  the program. SLADE-D computes dynamic deformations, velocities, stresses, and stress resultants occurring in the shell. Since it is  designed for use by a large number of people, it contains error checks wherever possible and, except where needed for efficiency, very straightforward logic. SLADE-D uses a single dimensioned storage array for the total stiffness matrix, mass matrix, and load  vector. If a given problem fits within the limits of this storage array, the program functions as an in-core program. If additional storage is required, the program seeks on-line auxiliary storage which must be randomly accessible.
top ]
8. RELATED AND AUXILIARY PROGRAMS

SLADE-D is an outgrowth of an earlier static shell program, SLADE.
top ]
9. STATUS
Package ID Status date Status
NESC0581/01 01-NOV-1975 Tested at NEADB
top ]
10. REFERENCES

Samuel  W. Key  and Zelma  E. Beisinger,  SLADE D,  A
Computer  Program  for  the  Dynamic   Analysis  of  Thin  Shells,
SLA-73-0079, January 1973.
             S.  W. Key  and Z.  E. Beisinger,  SLADE, A  Computer
Program  for the  Static Analysis  of  Thin Shells,  SC-RR-69-369,
November 1970.
top ]
11. MACHINE REQUIREMENTS

79,000 (decimal) words of core, extended core storage, and mass storage disk files.
top ]
12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NESC0581/01 FORTRAN-IV
top ]
13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:   SCOPE 3.2.
top ]
14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

   The
stiffness matrix, mass matrix, and load vector generated are stored  in A, a one-dimensional array of 6056 locations. If the matrices and vector generated require more than 6056 core locations, either random access extended core storage, random access mass storage disk files, or the equivalent is required. As the program is currently written, the mass storage calls WRITEC and READEC are used in conjunction with a CDC6635 extended core storage unit, and the mass  storage calls OPENMS, WRITMS, and READMS are used in conjunction with the system disk files.
The required number of blocks needed to store the stiffness matrix, mass matrix, and load vector is set up as one file of information in extended core storage or in disk file storage. Extended core storage is sought first, and, if the file length exceeds the space available, the file is placed in disk storage. Each block comprises 6056 core locations, located in the array A when in the core of the computer. The mass storage calls allow any number of words to be transferred to or from the file starting at any point in the file. The result is a randomly-accessible file. Any block is accessible at any time. The random access feature is required in the assembly of the stiffness matrix, mass matrix, and load vector in MERGEX. The time integration in INTEGX uses the file  sequentially.
top ]
15. NAME AND ESTABLISHMENT OF AUTHORS

                 S. W. Key and Z. E. Beisinger
                 Division 1541
                 Sandia Laboratories
                 P. O. Box 5800
                 Albuquerque, New Mexico  87115
top ]
16. MATERIAL AVAILABLE
NESC0581/01
File name File description Records
NESC0581_01.001 PROGRAM SOURCE (F4) 3507
NESC0581_01.002 SAMPLE PROBLEM DATA 61
NESC0581_01.003 SAMPLE PROBLEM PRINTED OUTPUT 637
top ]
17. CATEGORIES
  • I. Deformation and Stress Distributions, Structural Analysis and Engineering Design Studies

Keywords: deformation, finite element method, matrices, mechanical structures, shells, stresses.