Ship hull plating weld misalignment effects when subjected to tension
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Authors
Weaver, M. Cameron
Subjects
Advisors
Date of Issue
2001-06
Date
June 2001
Publisher
Monterey California. Naval Postgraduate School
Language
en_US
Abstract
Precision fabrication of ships is advancing. Welding is ubiquitous in ship construction and military standards have specified tolerances for joining plates in naval combatants. Precision manufacturing will allow the production of ships with smaller hull plate misalignments. A benefit from this could be improved ship survivability when subjected to underwater explosions. Slip Line Fracture Mechanics interacting with Finite Element Analysis (FEA) gives insight into the deformation, necking and fracture mechanisms of typical over-matched welds. The weld rotates with local necking until the plates are aligned and then shears off. FEA showed the importance of deformed geometry in promoting final fracture by slip from the toe of the weld in non-hardening material. Graphical results indicate that for a non-hardening material with an offset of 15% of the plate thickness, which is within current military standards, weld rotation of 4- 6 deg and local plate thinning of 4-5% in the region next to the weld can be expected. A test specimen showed a 4 deg weld rotation but did not provide the plane-strain condition and failed by necking away from the weld. A re-design is suggested.
Type
Thesis
Description
CIVINS (Civilian Institutions) Thesis document
Series/Report No
Department
Mechanical Engineering
Organization
Identifiers
NPS Report Number
Sponsors
Funder
CIVINS
Format
57 leaves ; 28 cm.
Citation
Distribution Statement
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.