Code is easy to use yet is general with respect to: (a) type of analysis to be performed; (b) geometry of shell meridian; (c) type of wall construction; (d) type of boundary conditions, ring supports, and branching configuration; and (e) type of loading

Bushnell, D.

English

NASA Technical Reports Server

November 1974	 B74-10205 
NASA TECH BRIEF 
S	 Langley Research Center 
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, Springfield, 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. 
Computer Program for
Stress, Stability, and Vibration of Complex Branched

Shells of Revolution: BOSOR 4 
.
The problem: 
A better method was needed to help engineers 
design branched shells of revolution. 
The solution: 
The BOSOR 4 computer program was developed in 
response to the need for a tool which would help 
engineers to design practical shell structures. An impor-
tant class of such shell structures includes segmented, 
ring-stiffened, branched shells of revolution. These 
shells may have various meridional geometries, wall 
constructions, boundary conditions, ring reinforcements, 
and types of loading including thermal loading. Support 
points, junctures, and ring reinforcements should be 
accurately modeled. Seemingly insignificant parameters 
sometimes have a large effect on stress, buckling loads, 
and vibration frequencies. 
How it's done: 
The BOSOR 4 program is very general with respect 
to the type of analysis which it will perform. Depending 
on the value of a control integer, the program will: (a) 
calculate axisymmetric stresses and displacements from 
a nonlinear theory for a series of stepwise-increasing 
thermal or mechanical loads; (b) determine critical loads 
corresponding to nonsymmetric buckling modes for 
a range of circumferential wave numbers, seeking the 
minimum load; (c) calculate vibration frequencies of 
prestressed shells corresponding to axisymmetric and 
nonsymmetric modes; and (d) calculate displacements 
and stresses in and buckling loads of nonsymmetrically 
loaded shells. 
The assumptions upon which the BOSOR 4 code is 
based are: 
a. The material is elastic. 
b. The thin shell theory is valid; that is, normals to the 
undeformed surface remain normal and undeformed.
c. The structure is axisymmetric; and in vibration 
analysis and nonlinear stress analysis, the loads 
and prebuckling or prestress deformations are axi-
symmetric. 
d. The prebuckling deflections, while considered finite, 
are moderate. That is, the square of the meridional 
rotation can be neglected compared to unity. 
e. In the calculation of displacements and stresses in 
nonsymmetrically loaded shells, linear theory is used. 
This branch of the program is based on standard 
small-deflection analysis. 
f. A typical cross-section dimension of a ring stiffener 
is small compared to the radius of the ring. 
g. The cross sections of the rings remain undeformed 
during the deformations of the structure, and the 
rotation about the ring centroid is equal to the 
rotation of the shell meridian at the attachment 
point of the ring (except, of course, if the ring is 
treated as a shell branch). 
It. The ring centroids coincide with the ring shear 
centers. 
i. If meridional stiffeners are present, they are numerous 
enough to include in the analysis by an averaging or 
smearing of their properties over any parallel circle 
of the shell structure. 
One of the more important extensions of the analysis 
is the capability of treating branched shells. This 
extension permits, for example: (a) the analysis of 
pressure hulls with bulkheads; (b) the treatment of ring-
stiffened shells as shells with branches, thus accounting 
for the deformation of ring cross sections; and (c) the 
investigation of double-hulled vessels. Two additional 
important extensions of the analysis include variable 
mesh-point spacing within each shell segment and a 
reformulation of the buckling eigenvalue problem to 
account for the prebuckling shape change of the shell 
in linear buckling analyses.
(continued overleaf) 
This document was prepared under the sponsorship of the National
	
Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	
will be free from privately owned riohts.
https://ntrs.nasa.gov/search.jsp?R=19740000205 2020-03-17T13:50:55+00:00Z
The BOSOR 4 code is easy to use yet is very 
general with respect to: (a) the type of analysis to be 
performed; (b) the geometry of the shell meridian; 
(c) the type of wall construction; (d) the type of 
boundary conditions, ring supports, and branching 
configuration; and (e) the type of loading.
Notes: 
1. This program was written in FORTRAN IV for the 
CDC 6000-series computers. 
2. Inquiries concerning this program should be directed 
to:
COSMIC 
112 Barrow Hall 
University of Georgia 
Athens, Georgia 30601 
Reference: LAR-1 1209 
Source: David Bushnell of
Lockheed Missiles and Space Co. 
under contract to
Langley Research Center
(LAR-1 1209)
ci 
. 
. 
B74-10205	 Category 09,06


Computer program for stress, stability, and vibration of complex branched shells of revolution: BOSOR 4

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