This work presents the numerical simulation of thin perfect, machined and repaired PVC pipes subjected to internally hydrostatic pressure, with ratio between the diameter (D) and the thickness (t), above or equal 20, D/t > 20. The numerical simulations were carried out with a finite element program, called Compshell, using PVC tubes, from elastic behavior to the failure. The boundary conditions were: clamped in one end and simple supported in the other, with freedom along the axial direction. The longitudinal and radial displacements, the bending moments and normal stresses resultants for pipes were evaluated. The maximum pressure was estimated using the Tsai-Hill failure criterion. The best result for repaired pipes was obtained with a laminate of epoxy matrix (E) filled with cotton cloth (C), since this composite and PVC Young's modulus are close to each other. The ideal composite repairing is the one that restores the structural stiffness of the affected region, in the way that it does not strangulate nor bulge out the tube. The purpose of the work is to compare the results obtained with two types of composite repairing for polymeric pipes: (i) epoxy matrix reinforced with E-glass fiber and (ii) epoxy matrix filled with cotton cloth, indicating the geometrical characteristics and mechanical proprieties of composite repairing that presented the best behavior.
Thin PVC pipes; composite repair
