THE FATIGUE STRENGTH OF FILLET WELDED CONNECTIONS

This report describes a study of the fatigue behavior of fillet welded joints stressed perpendicular to the weld line. The study included an experimental phase in which the stress-life and cracking behavior of load and non-load carrying fillet weld joints was determined. This experimental study concentrated on the fatigue behavior in the transition region between high and low cycle fatigue (10 to the third to 10 to the fifth cycles of load application). The second phase of the study was the determination of the fracture mechanics stress intensity factor for cracks at the weld toe or root of fillet welded joints. The finite element technique was used to determine the compliance of typical fillet welded joints. The results of this analysis showed that the stress intensity factor was a function of weld size, weld angle, plate thickness and weld penetration. Relationships to estimate the stress intensity factor were developed. The third phase of the study was the correlation of the experimental fatigue stress-life behavior of fillet welded joints with the predicted behavior using the concepts of the fracture mechanics of stable crack growth. The study showed that the fatigue behavior of various joint geometries could be correlated using the stress intensity factors developed in phase two. The correlation included failures from cracking at the root and toe of the fillet weld. The analysis provided a good estimate of the observed fatigue behavior for fatigue lives from 10 to the third to 2 times 10 to the seventh cycles of load application.

  • Corporate Authors:

    Lehigh University

    Fritz Engineering Laboratory
    Bethlehem, PA  USA  18015
  • Authors:
    • Frank, K H
  • Publication Date: 1971-10

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 162 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00033683
  • Record Type: Publication
  • Source Agency: Ship Structure Committee
  • Report/Paper Numbers: Rpt 358-37
  • Contract Numbers: N00014-68-A-0514
  • Files: TRIS
  • Created Date: Jul 28 1972 12:00AM