NESC0539 STRAP

1. NAME OR DESIGNATION OF PROGRAM:  STRAP

3. DESCRIPTION OF PROBLEM OR FUNCTION

The  code  STRAP  (STructural
Analysis  Package)  was  developed  to  analyze  the  response  of
structural  systems  to  static and  dynamic  loading  conditions.
STRAP-S  solves  for  the  displacements   and  member  forces  of
structural systems  under static loads and  temperature gradients.
STRAP-D  will  solve  numerically   a  given  structural  dynamics
problem.

4. METHOD OF SOLUTION

STRAP-S generates  the stiffness matrix  of a
structure by  the finite element  method and solves  the resulting
equations for structural displacements and member forces.  STRAP-D
generates  the  stiffness  matrix,   solves  for  eigenvalues  and
eigenvectors,  uncouples and  solves  the  series of  second-order
ordinary differential equations, and then calculates and plots the
requested member forces.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

   STRAP-S maxima -
        250 degrees of freedom
        100 members
   STRAP-D maxima -
        100 degrees of freedom
         80 time-steps in the forcing function input

6. TYPICAL RUNNING TIME

STRAP-S running time is about 5 seconds for
a  97  degree  of  freedom   problem.   STRAP-D  running  time  is
approximately 15 seconds for a plane  frame, 6 degrees of freedom,
6 modal  shape (0  to 1 second)  problem with  3 plots,  while 1.5
minutes are required for a vibrating  beam, 41 degrees of freedom,
2 modes (0 to 1 second) problem with 5 plots.

7. UNUSUAL FEATURES OF THE PROGRAM

STRAP-D allows forcing functions
input  to  be  in  the  form   of  pressures,  forces,  or  ground
accelerations.  Initial conditions  (displacements and velocities)
can be specified  as zero, or displacements can  be calculated, or
displacements  and velocities  can  be  read from  input.   Member
forces can be calculated and plotted by STRAP-D.

8. RELATED AND AUXILIARY PROGRAMS

Integral parts of STRAP-D include
an  eigenvalue-eigenvector   routine  (THJCOB)  by  C.   Noble,  a
stiffness  generator (STIFGN)  by  J.  A. Dearien,  a  Runge-Kutta
integration  technique  (RKINTZ)  by  R. D.  Peak,  and  a  matrix
inversion routine (MAINV) by D. H. Gipson.

10. REFERENCES

J. A. Dearien, C. Noble, and  E. D. Uldrich, STRAP, A
Computer  Code for  Static  and  Dynamic Structural  Analysis  and
Studies Made Using the Code, IN-1362, June 1970.
             J. A. Dearien, STRAP-S,  Structural Analysis Package-
Static, ANC Program Writeup, October 1969.
             L. J. Siefken, STRAP-D,  Structural Analysis Package-
Dynamic, ANC Program Writeup, October 1971.
             W.  Weaver,  Jr., Computer  Programs  for  Structural
Analysis, D. Van Nostrand Co., Inc., Princeton, New Jersey, 1967.
             W.  C.  Hurty  and  M.  F.  Rubinstein,  Dynamics  of
Structures,  Prentice-Hall, Inc.,  Englewood  Cliffs, New  Jersey,
1964.
             S.  L. Rogers,  Dynamics of  Framed Structures,  John
Wiley & Sons, Inc., New York, 1959.
             J. B.  Scarborough, Numerical  Mathematical Analysis,
The John Hopkins Press, Baltimore, Maryland, 1955.
             W.  T. Thomson,  Vibration  Theory and  Applications,
Prentice-Hall, Inc., Englewood Cliffs, New Jersey, 1965.
             N.  Willems and  W.  M.  Lucas, Matrix  Analysis  for
Structural Engineers,  Prentice-Hall, Inc., Englewood  Cliffs, New
Jersey, 1968.

     - J. A. Dearien, C. Nobel, and E. D. Uldrich;
       STRAP, A Computer Code for Staistic and Dynamic Structural
       Analysis and Studies Made Using the Code, IN-1362, June 1970.
     - J. A. Dearien;
       STRAP-S, Structural Analysis Package-Static, Program Writeup,
       October, 1969.
     - L. J. Siefken;
       STRAP-D, Structural Analysis Package-Dynamic, Program
       Writeup, October 1971.

     - J. A. Dearien, C. Nobel, and E. D. Uldrich;
       STRAP, A Computer Code for Static and Dynamic Structural
       Analysis and Studies Made Using The Code, June 1970.
     - J. A. Dearien;
       STRAP-S, Structural Analysis Package-Static, Program Writeup,
       October 1969.
     - L. J. Siefken;
       STRAP-D, Structural Analysis Package-Dynamic, Program
       Writeup, October 1971.

11. MACHINE REQUIREMENTS

300K bytes of memory  for each program plus
5 to  7 direct  access storage  devices besides  standard I/O  for
STRAP-D

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:   OS/360.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

STRAP-D uses plotting subroutines currently  in the NRTS operating
system.

15. NAME AND ESTABLISHMENT OF AUTHORS

                 J. A. Dearien and E. D. Uldrich
                 EG&G Idaho, Inc.
                 P. O. Box 1625
                 Idaho Falls, Idaho  83401

File name	File description	Records
NESC0539_01.001	INFORMATION	2
NESC0539_01.002	DD-CARDS FOR ALL 3 EXECUTION STEPS	29
NESC0539_01.003	STEP-1 SOURCE PROGRAM (F4)	2081
NESC0539_01.004	STEP-1 SAMPLE PROBLEM INPUT DATA	68
NESC0539_01.005	STEP-1 SAMPLE PROBLEM PRINTED OUTPUT	232
NESC0539_01.006	STEP-2 SOURCE PROGRAM (F4)	2413
NESC0539_01.007	STEP-2 SAMPLE PROBLEM INPUT DATA	58
NESC0539_01.008	STEP-2 SAMPLE PROBLEM PRINTED OUTPUT	5446
NESC0539_01.009	INFORMATION	2
NESC0539_01.010	STEP-3 SOURCE PROGRAM (F4)	624
NESC0539_01.011	STEP-3 SAMPLE PROBLEM INPUT DATA	3
NESC0539_01.012	STEP-3 SAMPLE PROBLEM PRINTED OUTPUT	12

File name	File description	Records
NESC0539_02.001	INFORMATION	2
NESC0539_02.002	SOURCE PROGRAM (F4)	1226
NESC0539_02.003	SAMPLE PROBLEM INPUT DATA	13
NESC0539_02.004	SAMPLE PROBLEM PRINTED OUTPUT	97