Abstract:

In this article, all definitions of pipe-string neutral point mentioned in previous occasions and their mechanical properties are analyzed in detail. The relationship between the neutral point, the axial zero-stress point and the neutral section is discussed. Answers are presented to such problems as whether the neutral point is the unstable demarcation point of the pipe-string while bent. This is beneficial to the correct understanding of the neutral point and its effect on engineering.

Key words: Pipe string, Stress, Neutral point, Axial zero-stress point, Unstable demarcation point