Publication:
A study of pull-through failures of mechanically fastened joints.

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Authors
Freedman, Robert N.
Subjects
through-plane shear
joint failures
fastener pull-through
composite plates
Advisors
Ball, R.E.
Date of Issue
1977-09
Date
September 1977
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The relationship between the bending moment and the through-plane shear force in the vicinity of a mechanical fastener at failure was determined. Experiments were conducted on 4-inch wide flat plate aluminum and graphite-epoxy composite specimens that modeled portions of a wing skin along a spar and along a rib. The composite specimens were either 8-ply or 16-ply balanced layups and were simply supported at two opposing edges and free along the other two edges. The fasteners were pulled normal to the plates, and the maximum force at failure was measured for specimen lengths varying from two to six inches between supports. The aluminum plates failed by formation of a plastic hinge across their width and showed little sensitivity to through-plane shear. The 8-ply spar specimens cracked across their width and also were relatively insensitive to through-plane shear. However, failures of the rib specimens were confined to a region near the fastener, where the fastener pulled through the plate, and showed much greater sensitivity to through-plane shear. Two analyses were made; one for small elastic deflections of a thin orthotropic plate, and another for a beam in the elastic range. A mesh generator for a finite element model of the plate around the fastener was also developed for the computer program ADINA.
Type
Thesis
Description
Series/Report No
Department
Aeronautics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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