EFFECT OF BIAXIAL LOADING ON THE FRACTURE-BEHAVIOR OF A FERRITIC STEEL-COMPONENT

The effect of biaxial loading on the ductile behaviour of a through-wa ll crack in a ferritic steel structure under contained yield is of par ticular interest to the structural integrity argument for reactor pres sure vessels. This results from the fact that there are many instances in practice (for example a crack in a circumferential weld), where a significant applied stress is present in the direction parallel to the crack as well as in the perpendicular direction. Two large plate duct ile tearing tests have been performed on centre through-crack specimen s (75 mm by 2 m by 2 m) manufactured from a ferritic steel. The first test specimen was loaded in uniaxial tension and the second test speci men was loaded biaxially. This paper presents experimental details and results of the two plate tests and describes the analysis work undert aken to interpret the experiments satisfactorily.