Repair of Internal and External Circular Failures Using Winding Technology

Abstract

The first part of the paper deals with the FEM computation of deformations, stresses and strain in the surrounding area of internal and external circular artificial failures with a set of given geometrical dimensions in steel pipelines. For the investigation of this problem three groups of mechanical models are applied: multilayered elastic shell, 3D elastic solid and 3D elastic-plastic solid FEM models. The aim of this analysis is to clarify the case in which the pipeline fails. When a pipe fails and needs repair or reinforcement, this is called critical case.  In the second part of the paper the repaired pipes are investigated. For repairing of the internal and external failures, internal or external multilayered textile composite reinforcements are applied by winding technology. The task is to determine the width of the reinforcement and the number of layers needed for repair.  The different mechanical models (multilayered elastic shell, 3D elastic solid and 3D elasto-plastic solid) are compared on the basis of numerical results. The critical cases are determined and the questions of repair are answered also numerically.