Pipe circularity reformation via line heating

Abstract

Fabrication of pipes requires the use of several manufacturing processes, such as bending, welding, drilling and wringing. However, in most cases the circular ends deviate from true circles and need reformation to be welded to angles. Currently the reformation is conducted by hammering and relies on the intuition of skilled workers. This reforming process is not only expensive but also generates unhealthy loud noise. The objective of this research is to develop an automatic system of circularizing the ends of a deformed pipe by laser line heating. The overall problem is defined as follows: Given the design of a metal pipe, measure the shape of the cross sections of both ends and a branch end of the manufactured pipe and determine the heating paths together with the heating conditions to reform the manufactured pipe to within acceptable tolerances with respect to the designed pipe using the line heating method. The line heating conditions to be applied to the pipe have to be determined in real time to make the process ecient. A Neural Network is created for this purpose and the database used to run it is generated using a simplified thermo-mechanical model of the pipe validated by a Finite Element Model (FEM).