Open Access

ARTICLE

Fracture Mechanics Approach to Estimate Fatigue Lives of Welded Lap-Shear Specimens

¹Poh-Sang Lam², Jwo Pan³

1 This manuscript has been authored by Savannah River Nuclear Solutions, LLC under ContractNo. DEAC09- 08SR22470 with the U.S. Department of Energy. The United States Governmentretains and the publisher, by accepting this article for publication, acknowledges that the UnitedStates Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish orreproduce the published form of this work, or allow others to do so, for United States Governmentpurposes.
2 Materials Science & Technology, Savannah River National Laboratory, Aiken, South Carolina, U.S.A.
3 Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, U.S.A.

Computers, Materials & Continua 2015, 46(1), 1-16. https://doi.org/10.3970/cmc.2015.046.001

Abstract

A full range of stress intensity factor solutions for a kinked crack with finite length is developed as a function of weld width and the sheet thickness. When used with the main crack solutions (global stress intensity factors) in terms of the applied load and the specimen geometric parameters, the fatigue lives of the kinked crack can be estimated for the laser-welded lap-shear specimens. The predicted curve for the load range-fatigue life passes through the cluster of experimental data and is in good agreement. A classical solution associated with an infinitesimal kink is also employed. However, its life prediction tends to overestimate the actual fatigue life. In addition, the traditional fatigue life estimation based on structural stress is performed for completeness. This non-fracture mechanics approach only agrees well with the experimental data under high cyclic load conditions.

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Keywords

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