Efficiency Assessment of the Composite Materials Repair Systems Intended for Corrosion Damaged Pipelines

Abstract

This paper presents the results of the research work carried out by the authors in order to evaluate the efficiency of the composite material wraps/sleeves (made of a polymeric matrix and reinforcing fabric) used to repair steel pipelines carrying hydrocarbons upon which local metal loss defects (generated by corrosion and/or erosion processes) have been detected. The pipeline repair technologies consisting of the application of composite material wraps are perceived as being advantageous alternative solutions for substituting the conventional technologies, which require welding operations to be performed in the pipe areas with defects. The efficiency of the composite repair systems has been investigated by assessing the reinforcement effects (the restoration level of the damaged pipe mechanical strength) generated by the applied composite wraps as a function of their geometry and mechanical properties. To that purpose, numerical models based on finite elements have been developed and certified by comparing them with the results of several experimental programs previously performed by the authors. Finite elements simulations have also been conducted in the plastic region, taking into account material non-linearity. The calculation methods proposed in literature (among which a method previously developed by the authors) to define the composite wrap dimensions (thickness and length) for a given pipe have also been investigated and compared to our numerical results in order to select the most adequate solution for the design of the composite repair system. The optimal values for the mechanical properties of the composite material used by the repair system have also been defined.

Corrosion Repair of Pipelines Using Modern Composite Materials Systems: A Numerical Performance Evaluation

“…In order to select the most adequate method for the design of the composite wraps used for steel pipes repair, two relevant case studies have been analyzed using such simulations. The results and conclusions of these analyses, detailed in [21], are briefly described in this paper.…”

“…A typical repair system using composite materials, intended for steel pipes repair, consists of the following elements [20][21][22]:…”

“…A simulations. The results and conclusions of these analyses, detailed in [21], are briefly described in this paper.…”

“…In addition to our previous investigations from [21][22][23], the effects in the composite repair design procedure of the defect circumferential extent (width), of its orientation with respect to the steel pipe axis and of the fillet radius used when machining the defect area (as required by the typical repair procedure) have been investigated and the results are discussed in the present paper.…”

“…All the investigations performed in the present paper, as well as in [21], have taken into account only the most relevant mechanical loading affecting transmission pipelines, i.e., the internal pressure. No additional loads or temperature variations have been considered in our analyses.…”