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http://dx.doi.org/10.3795/KSME-A.2011.35.10.1179

Fracture Mechanics Approach to X-Ray Diffraction Method for Spot Welded Lap Joint Structure of Rolled Steel Considered Residual Stress  

Baek, Seung-Yeb (Dept. of Mechanical Design Daelim Univ.)
Bae, Dong-Ho (School of Mechanical Engineering, Sungkyunkwan Univ.)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.35, no.10, 2011 , pp. 1179-1185 More about this Journal
Abstract
Cold and hot-rolled carbon steel sheets are commonly used in railroad cars or commercial vehicles such as the automobile. The sheets used in these applications are mainly fabricated by spot welding, which is a type of electric resistance welding. However, the fatigue strength of a spot-welded joint is lower than that of the base metal because of high stress concentration at the nugget edge of the spot-welded part. In particular, the fatigue strength of the joint is influenced by not only geometrical and mechanical factors but also the welding conditions for the spot-welded joint. Therefore, there is a need for establishing a reasonable criterion for a long-life design for spot-welded structures. In this thesis, ${\Delta}P-N_f$ relation curves have been used to determine a long-life fatigue-design criterion for thin-sheet structures. However, as these curves vary under the influence of welding conditions, mechanical conditions, geometrical factors, etc. It is very difficult to systematically determine a fatigue-design criterion on the basis of these curves. Therefore, in order to eliminate such problems, the welding residual stresses generated during welding and the stress distributions around the weld generated by external forces were numerically and experimentally analyzed on the basis of the results, reassessed fatigue strength of gas welded joints.
Keywords
Spot Welded Joint; Residual Stress; Fatigue Strength; X-Ray Diffraction Method; Fatigue Design Criterion;
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Times Cited By KSCI : 1  (Citation Analysis)
Times Cited By SCOPUS : 0
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