报告题目： Influence of discontinuous yielding on structural integrity
个人介绍：After obtaining bachelor and master in China and UK, respectively, Longjie Wang started doctoral research in 2014 at Brunel University London in collaboration with National Structural Integrity Research Centre (NSIRC) and The Welding Institute (TWI). His research topic is ‘Fracture assessment of cracked pipelines subjected to large plastic deformation in the presence of yielding discontinuity’. His research interests include strain-based fracture assessment of pipelines, the effect of Lüders band on fracture and residual stresses in weldments.
Discontinuous yielding can often occur in mild steels, usually manifested with localised plastic bands during uniaxial tensile tests. This phenomenon is induced by a process called strain ageing in which the interstitial atoms interplay with the dislocations, forming obstacles against plastic deformation.
Discontinuous yielding has usually been found in a range of engineering sectors, including oil and gas, nuclear, manufacturing, etc. A number of studies have shown that discontinuous yielding may compromise the serviceability of engineering components, leaving current assessment procedures potentially non-conservative. Despite that this phenomenon has been extensively investigated by material scientists, its influence on structural integrity, especially for cracked components, has not been well-understood. Thus, an in-depth understanding of how discontinuous yielding affects structural integrity is of importance.
This talk will introduce the influence of discontinuous yielding on structural integrity with a focus on fracture behaviour, numerical simulation of discontinuous yielding, recent findings and outlook for future research.