ON CRACKS IN WELDS AND WELDED STRUCTURES

This paper summarizes some findings on cracks in welded structures made during various research studies--in particular, certain aspects of a major long-term research program on low-cycle fatigue are included. The structural behavior of welded plate girders is relatively unaffected by large cracks for a substantial proportion of life. Initiation of a crack in a welded plate girder is usually due to exhaustion of ductility caused by secondary bending. Both the lumped-parameter method and the use of finite elements are successful in predicting the state of stress in a cracked plate or in a cracked weld. Significant reduction in test scatter can be realized through consideration of geometric effect of penetration in fillet welds. The error in predicting total life is due to the error in the estimation of growth rates when the crack is small. A relationship exists at the onset of rapid fracturing such that the rate of change of crack-opening-dislocation is equal to the rate of crack extension. The overall study is seeking an advancement of understanding in fundamental as well as in practical terms.

• Corporate Authors:

  Lehigh University

  Department of Mechanical Engineering
  Bethlehem, PA  United States  18015
• Authors:
  • Tall, L
• Publication Date: 1971-5

Media Info

• Features: References;
• Pagination: 35 p.

Subject/Index Terms

• TRT Terms: Cracking; Fracture mechanics; Joints; Measurement; Welds
• Uncontrolled Terms: Crack propagation; Welded joints
• Old TRIS Terms: Crack opening measurement; Low cycle fatigue
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00032632
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: Rpt No. 358.30
• Contract Numbers: N00014-68-A-0514
• Files: TRIS
• Created Date: Apr 21 1974 12:00AM