A Technique to Produce Automatic Welds with Enhanced Fatigue Crack Propagation Lives under Transverse Loading

CHAPETTI, M.D.; OTEGUI, J. L.

INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 1997 vol. 70 p. 173 - 181

0308-0161

In order to contribute to the development of an automaticweld process that introduces a controlled degree of irregularity to the weld toe, as a means to enhance the development and interaction of cracks and improve fatigue resistance, the double arc rotating technique (DART) was developed. Beadon-plate welds were fabricated using this method. Weld toes were fatigue tested by three point bending in the transverse and longitudinal directions. The fatiguepropagation behaviour of cracks growing from the weld toes, and its relationship with defined geometric parameters, were modeled using a fracture mechanics model. Compared with standard straight welds, fatiguelife improved up to 111% when loaded in the transversal direction, while decreased about 10% in the longitudinal direction. Afatiguelife prediction method for welds with controlled toe irregularity, considering defined toe geometry parameters, is presented, and results are discussed.