EXPERIMENTAL STUDY ON UNEVEN DEFORMATION OF INFLATING PIPE DURING INFLATION

By simulating the real dynamic environment in the hole, an experimental study aimed at discovering the changing tendency of pipe wall thickness unevenness and pipe unroundness in five different inflating ranges was conducted using the 35CrMo steel pipe. It was discovered that after inflation, the unevenness and unroundness became even larger, and crack detection and analysis found some defects in some parts of the inflating pipe. However, the defects are different in the longitudinal direction of the pipe. It shows that severe uneven deformation happens to the inflating pipe during inflation. Factors causing this uneven deformation were analyzed and it is concluded that the uneven deformation is one of the main factors causing the reduction of pipe collapsing strength. This study is valuable for composing the practical standards for inflating pipe materials and the research on inflating technology design.