A Strain Gauge Technique for Monitoring Small Fatigue Cracks in Welds

J,L. OTEGUI; D. BURNS; U. MOHAUPT

ENGINEERING FRACTURE MECHANICS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1991 vol. 40 p. 549 - 569

0013-7944

Atechnique has been developed to monitor growth and closure levels of mildly irregular single and multiple cracks growing at the toe of welds. It is based on measurements of strain at several positions on the plate surface, near the weld toe. Calibration procedures for crack shape measurements are given, and numerical models are compared with experimental results. Finally, some experimental determinations of crack closure levels are presented. Surface cracks as small as 0.2 mm deep can be confidently detected. Accurate measurements of crack depth, surface length and closure levels can be obtained for cracks deeper than about 0.4 mm