Importance of Toe Irregularity on Fatigue Resistance of Automatic Welds

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

INTERNATIONAL JOURNAL OF FATIGUE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 1995 vol. 17 p. 531 - 538

0142-1123

The early propagation stages of fatigue cracks along the toe of automatic bead-on-plate welds in a structural steel are studied. Three methods to introduce a controlled degree of waviness on the weldtoe, to optimize the degree of crack interaction during fatigue growth, were tested: arc rotation, variable arc voltage and variable weld speed. The development of fatigue cracks in seven specimens was monitored using a strain-gauge method and beach marking. Crack mismatch and depth to coalescence were found to be much smaller in the case of straight welds, which also showed shorter propagation lives. The period of toe waves, as well as local toe geometry, strongly influence fatigue crack initiation and propagation lives. Best fatigue life improvements were obtained with arc rotation techniques