Effect of Precompression on Ovality of Pipe After Bending

Abstract

Ovality is a main defect in all pipe bending techniques. An objective of the work is to control ovality in pipe bending. A new concept is suggested for reducing the flattening or ovality. Based on the concept, a mechanism is developed for bending pipes. This mechanism has provisions for precompression of the pipe along the directrix of maximum deformation during bending. Experimentation is carried out on this mechanism and dimensions are measured at 13 discrete places along the length of the pipe. Percentage ovality is computed using experimental results. It is justified by using equations of radius and displacement functions. Minimization of potential energy by sequential search method is done. The methodical approach is presented in this paper. Results show that precompression reduces ovality of the pipe after bending.