Experimental and computed stress distribution ahead of a notch in a pressure vessel: Application of T-stress conception

The work presents the experimental and numerical study of stress–strain distribution near longitudinal and circumferential external defects of semi-elliptical shape in pressurised steel’s pressure vessel, which have proved that proposed numerical analysis is reliable for assessments of the T-stress and parameter of biaxiality β, parameter to characterise stress state with the aim to forecast the potential path of defects propagation. For considered cases it has been shown that the fracture process is expected as potentially stable, i.e. it will be propagated in the plane of the initial longitudinal or circumferential defect. It was also shown that the stress conditions for stable propagation is earlier achieved for circumferential defect than for longitudinal.