NASA Technical Reports Server (NTRS) 20110014680: Program Calculates Forces in Bolted Structural Joints

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by  NASA Technical Reports Server (NTRS)

This program was written by Paul L. Luz shear forces in the individual bolts. The • Automate repetitive processes in test-
of Marshall Space Flight Center. For fur- program identifies which bolts bear the ing and analysis;
ther information, contact Sammy Nabors, greatest axial and/or shear loads. The • Accelerate pre-test analysis;
MSFC Commercialization Assistance Lead, program also performs a “fail-safe” analy- • Accelerate reporting of tests;
at [email protected]. Refer to sis in which the foregoing calculations are • Facilitate planning of tests;
MFS-31796. repeated for a sequence of cases in which • Improve execution of tests;
each fastener, in turn, is assumed not to • Create a vibration, acoustics, and
transmit an axial force. shock test database; and
This program was written by Daniel A. • Integrate analysis and test data.
Program Calculates Forces Buder of The Boeing Company for Johnson The software package includes mod-
in Bolted Structural Joints Space Center. ules pertaining to sinusoidal and ran-
A FORTRAN 77 computer program cal- Title to this invention, covered by U.S. dom vibration, shock and time replica-
culates forces in bolts in the joints of struc- Patent No. 5,884,232 has been waived tion, acoustics, base-driven modal
tures. This program is used in conjunc- under the provisions of the National Aero- survey, and mass properties and
tion with the NASTRAN finite-element nautics and Space Act {42 U.S.C. 2457 (f)}. static/dynamic balance. The program is
structural-analysis program. A mathemati- Inquiries concerning licenses for its commer- commanded by use of ActiveX controls.
cal model of a structure is first created by cial development should be addressed to: There is minimal need to generate com-
approximating its load-bearing members The Boeing Company mand lines. Analysis or test files are se-
with representative finite elements, then Rocketdyne Propulsion & Power lected by opening a Windows Explorer
NASTRAN calculates the forces and mo- 6633 Canoga Avenue display. After selecting the desired input
ments that each finite element con- P.O. Box 7922 file, the program goes to a so-called
tributes to grid points located throughout Canoga Park, CA 91309-7922 analysis data process or test data process,
the structure. The user selects the finite Phone: [phone] depending on the type of input data.
elements that correspond to structural Fax: [phone] The status of the process is given by a
members that contribute loads to the E-mail: [email protected] Windows status bar, and when process-
joints of interest, and identifies the grid Refer to MSC-23121, volume and number ing is complete, the data are reported in
point nearest to each such joint. This pro- of this NASA Tech Briefs issue, and the graphical, tubular, and matrix form.
gram reads the pertinent NASTRAN out- page number. This work was done by Daniel Kaufman of
put, combines the forces and moments Goddard Space Flight Center. Further in-
from the contributing elements to deter- formation is contained in a TSP (see page 1).
mine the resultant force and moment act- This invention is owned by NASA, and a
ing at each proximate grid point, then Integrated Structural Analy- patent application has been filed. Inquiries con-
transforms the forces and moments from sis and Test Program cerning nonexclusive or exclusive license for its
these grid points to the centroids of the An integrated structural-analysis and commercial development should be addressed to
affected joints. Then the program uses structure-testing computer program is the Patent Counsel, Goddard Space Flight Cen-
these joint loads to obtain the axial and being developed in order to: ter, [phone]. Refer to GSC-14775-1.
16 NASA Tech Briefs, January 2005