TWI Industrial Member Report Summary 581/1996
H G Pisarski
Current standard fracture toughness test methods are based on testing specimens taken from plain, homogeneous materials.
These test methods do not consider the distortion curvature and residual stresses often present when testing specimens taken from welded product forms. Tests on weld metals and heat affected zones require special procedures to evaluate fracture toughness. Furthermore, the differences in tensile properties between the notched region and adjacent material on the deformation behaviour of the specimen are ignored by standard CTOD and J estimation procedures. These factors can affect the result and the outcome of defect assessment analyses and, therefore, need to be recognised when designing the appropriate test to measure fracture toughness.