Brittle Fracture in Heavy Section Welded T-Joints: Correlation Between Stress Intensity at Fracture and Small-Specimen Toughness Tests

A fracture mechanics analysis has been made of brittle fractures encountered during a program of fatigue tests of welded plate T-joints. Fracture toughnesses are in reasonable agreement with small-sample test results, if the following factors are taken into account: a specimen size effect (with larger samples having lower toughness); existence of a substantial contribution to the stress intensity factor from residual stresses; and shakedown of residual stresses, with shakedown increasing with increasing applied stress.