Computer program GD203 develops transfer functions to compute governing vibration environment for complex structures subjected to a base motion

Ernst, C.

Jones, P. J.

English

NASA Technical Reports Server

November 1971	 Brief 71-10441 
NASA TECH BRIEF 
Marshall Space Flight Center	
_ilv 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Sprngfield, Virginia 22151. Requests for individual copies or questions relating to the. Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Vibrational Transfer Functions for Base Excited Systems 
S
The problem: 
To compute the vibrational transfer functions for 
complex structures subjected to a specified base 
moton. In the design of a complex structure, the 
governing vibration environment is generally speci-
fied in terms of either a sinusoidal or random base. 
The solution: 
A computer program, GD203, which develops 
transfer functions for complex structures subjected 
to a base motion. 
How it's done: 
An analytical model of the structure is developed, 
and the analytical modal (natural frequencies and 
mode shapes) and model properties are used in a 
response analysis to determine system transfer func-
tions. The analytical model consists of mass and 
stiffness matrices generally developed for lumped 
parameter systems using finite element techniques. 
For complex structures, the total system model 
properties are sometimes developed through modal 
coupling techniques. 
The methodology and the computer program re-
quire external development of the system model 
properties, but have the flexibility to utilize modal 
properties developed from modal coupling tech-
niques. The program is also capable of plotting 
the computed transfer functions.
This program has been successfully utilized to 
predict the response of complex aerospace struc-
tures to specified random and sinusoidal base excita-
tion. It has also been applied to the problem of 
determining payload response to a test level pay-
load/booster interface environment. 
Notes: 
1. The program considers base excitation only. 
2. This program is written in FORTRAN V for use 
on the CDC-6000 series computers. 
3. Requests for further information may be directed 
to:
COSMIC 
112 Barrow Hall 
University of Georgia 
Athens, Georgia 30601 
Reference: B71-10441 
Patent status: 
No patent action is contemplated by NASA. 
Source: P.J. Jones and C. Ernst of
Martin Marietta Corp. 
under contract to
Marshall Space Flight Center
(M FS-21432)
Category 09 
This documeft was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned.rights.
https://ntrs.nasa.gov/search.jsp?R=19710000438 2020-03-17T02:30:44+00:00Z


Vibrational transfer functions for base excited systems

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