UNE-EN ISO 15653:2018

This International Standard specifies methods for determining fracture toughness in terms of K (stress

intensity factor), ´ (crack tip opening displacement, CTOD) and J (experimental equivalent of the J-integral) for

welds in metallic materials.

This International Standard is complementary to ISO 12135, which covers all aspects of fracture toughness

testing of parent metal and which needs to be used in conjunction with this document. This International

Standard describes methods for determining point values of fracture toughness. It should not be considered a

way of obtaining a valid R-curve (resistance-to-crack-extension curve). However, the specimen preparation

methods described in this International Standard could be usefully employed when determining R-curves for

welds. The methods use fatigue precracked specimens which have been notched, after welding, in a specific

target area in the weld. Methods are described to evaluate the suitability of a weld for notch placement within

the target area, which is either within the weld metal or within the weld heat-affected zone (HAZ), and then,

where appropriate, to evaluate the effectiveness of the fatigue crack in sampling these areas.