长输管道的韧性设计

为保证长输管道系统的安全可靠，韧性设计是管道设计的重要指标，足够的韧性可以延缓或阻止断裂事件的进程。管道韧性设计基本出发点是安全性和经济性，综合平衡这两方面因素，并在断裂力学的基础上，提出了管道韧性设计的基本原则，即开裂控制原则，裂纹扩展的止裂原则和封口形原则。开裂控制原则提出了根据ＣＶ与钢管全壁厚临界缺陷尺寸的关系曲线，来确定相应管道对于开裂控制的韧性设计要求；裂纹扩展的止裂原则是根据Ｗ．Ａ．ｍ

Toughness Design of Trunk Pipeline

As an important factor in pipeline design, sound pipeline toughness design can guarantee safe and reliable operation and delay or avert fractures. The focuses of attention for pipeline toughness design are safety and e-conomic rationality. With these two factors synthesized, the following basic principles for pipeline toughness design are presented on the basis of fracture mechanics : the principles of fracture control, fracture propaga- tion arresting and fracture pattern. Fracture control principle means to decide upon the requirements of pipe toughness design for fracture conyol according to the curve of Cv vs. critical pipe thickness; Fracture propagation arresting principle is that according to the CVN method which can predict toughness fracture and which was presented by W. A. Maxey ,the strength, the higher the working pressure and the larger the pipe diameter, the higher the toughness required. The fracture pattern principle points out that ,according to the relation between tearing rate and fracture shear area(SA),the design and evaluation criterion for pipe toughness shall be 80% - 85% FATT of the DWTT. The following factors having effect on pipe toughness are analysed: line pipe strength and design level, pipe thickness and diameter, medium transported, locations in pipe environmental impact,etc.