Characterizing dynamic fracture toughness of linepipe steels using the pressed-notch drop-weight-tear test specimen

摘要

This paper presents the development of a procedure for calculating the dynamic J-R curve from the load-displacement trace of a pressed-notch drop-weight-tear test specimen. The slope of the J_M-R curves generated provides technical insight into the range of steady-state propagation that occurs during these experiments. The slope of the J_M-R curve (dJ_M/da) is compared to visually measured crack-tip-opening angle values and conclusions about the relationship between these parameters and the steady-state crack propagation resistance are made. These results are key in the development of a procedure to predict axial crack arrest in gas pipelines from laboratory specimen data.