Constraint-corrected J (CTOD) resistance curves for strain-based design of pipelines

基于应变的方法被广泛认为是设计承受较大塑性变形的管道的唯一可行方法，例如承受冻胀和融沉引起的地面移动的管道。管道环焊缝的拉伸应变能力对于基于应变的管道设计是至关重要的，因为它是管道和焊接材料选择以及焊接工艺评定的决定性因素之一。为了准确评估管道环焊缝的拉伸应变能力，通常包含焊接过程中引入的缺陷，需要进行宽板试验或材料断裂韧性直接或间接评估。该项目的目标是开发中高强度管线钢和管道环缝的约束校正断裂韧性阻力曲线，以及预测宽板拉伸应变能力的分析程序。这项研究将在TransCanada提供的现金和实物支持下进行，为期三年。一名博士后研究员(PDF)和一名博士生将接受该项目的培训。

The strain-based methodology is widely considered as the only viable option for designing pipelines subjected to large plastic deformations, e.g. pipelines subjected to frost heave- and thaw settlement-induced ground movements. The tensile strain capacity of the pipeline girth weld is of critical importance to the strain-based design of pipelines because it is one of the governing factors for the selection of the pipe and weld materials as well as the qualification of the welding process. To accurately evaluate the tensile strain capacity of the pipeline girth weld, which in general contains imperfections introduced by the welding process, a wide-plate test or material fracture toughness is needed for a direct or indirect assessment. The objective of the proposed project is to develop constraint-corrected fracture toughness resistance curves for medium- to high-strength pipeline steels and pipeline girth welds, and an analytical procedure to predict the tensile strain capacity of the wide plate. The research will be carried out for a period of three years with the cash and in-kind supports from TransCanada. One postdoctoral fellow (PDF) and one PhD student will be trained in the project.