Deformation Mechanism Analysis of Three-Roller Continuous and Synchronous Calibration Process of Straightness and Roundness For LSAW Pipes

Abstract

Continuous and synchronous calibration process of straightness and roundness for LSAW (Longitudinally Submerged Arc Welding, LSAW) pipes with three rollers is a bidirectional reciprocating bending process that includes axial and circumferential directions. It is particularly important to reveal the deformation mechanism, which provides theoretical support for the calibration process to be applied to actual production. Based on this, through the combination of references, theoretical analysis and numerical simulation, the deformation mechanism is analyzed in this paper. The whole deformation process of pipe is modeled and then numerically simulated with FEM software of ABAQUS. The results show that reciprocating bending can eliminate the difference of initial curvature, so that the axial curvature and circumferential curvature are unified to the same direction and value respectively. The synergy between the axial reciprocating bending straightening process and the circumferential reciprocating bending rounding process realizes the calibration process of LSAW pipes. The simulation results support the theoretical results, and the deformation is mainly caused by axial stress and circumferential stress.

The JCOE/JCOC manufacturing process and collapse resistance of submarine pipeline

“…The current pipeline standard API (American Petroleum Institute) Spec 5L 23 stipulates that the roundness of pipe should not exceed 1.5% of the diameter (0.75% when the pipe is used offshore). To effectively reduce the ovality of the pipeline, the pipe calibration methods mainly include expanding process, [24][25][26][27][28][29][30] compression process, 25,[31][32][33][34][35] over-bending setting round by mold press type method, 36 internal expansion over bending and calibration (IEOBC) process, 37 the symmetrical threeroller setting round process, [38][39][40] the process of continuous and synchronous calibration of roundness and straightness by three rollers, [41][42][43][44][45][46] and so on. Zhai et al 37 built the intelligent control system of IEOBC process, which is mainly used for pipe end rounding .…”

“…Yu et al 38 proposed the symmetrical three-roller setting round process, built the mechanical model and numerical simulation model, 39 and carried out theoretical analysis and experimental research on process parameters. 40 Huang et al 41 developed the symmetrical three-roller setting round process, which applies to thin-walled pipe, studied the process parameters, roller design, 42 mechanical model, 43 stress strain distribution, 44 deformation mechanism, 45 and weld influence. 46 At present, expanding and compression processes are mainly used to calibrate pipes in the industry.…”