Repair of small damages in steel pipes with composite patches

Abstract

The temperature change, internal pressure and corrosion are main reason of cracks in pipes. Removal of damaged pipes with new ones gives rise to major disruption during operation. This causes loss of time and cost. This study aims to prevent crack propagation and to obtain fast repair in damaged area, at the beginning of the damage. Repair of small cracks in steel pipes using composite patches has been studied in this work. The aim of the study is to repair small cracks less than 8 mm length. For this purpose, holes with 8 mm diameters were drilled in 170 mm long pipes and composite patches with 2, 2.6 and 3.2 mm thickness and 35, 40 and 45 mm overlap lengths with 60, 90 and 120° overlap angles were attached with an adhesive of 0.2 mm thickness. The repaired pipes were subjected to internal pressure until damage occurred. A finite element model was developed and the numerical results were verified based on experiments. The repair of steel pipe with adhesive bonding was successfully achieved under high pressure with composite patches. The results show that the increase in overlap angle results in an increased surface area, and consequently an increase in failure load. Furthermore, the failure load increased with an increase in patch thickness. Additionally, it is seen that the failure load does not change significantly with increasing patch thickness.

Investigation of Ballistic Behavior of Agricultural Waste Doped Hybrid Composite Plates in Vacuum Infusion Method

“…One of the most important applications of composite materials in these areas is the damage repair of pipes due to internal pressure and varying temperature rates. In the repair of damaged galvanized steel pipes, three different types of patch materials, composite, aluminum and steel, were selected and the effect of these types on one type of adhesive was investigated [5,6].…”

Numerical analysis of repaired wall loss defect pipelines for optimum composite wrap thickness

“…Theisen and Keller [34] conducted numerical and experimental tests for both patch and wrap repairs on through-wall defects and they reported the maximum strain of patch is higher than with composite wrap type system [34]. Ayaz et al [35] showed that the increment in overlap length could enhance the failure strength in composite patch repair system for a through wall defect. This indicate, the FRP patch repair system can be a good choice for small-area though wall defect and wall loss defect.…”

Predicting the effect of adherend dimensions on the strength of adhesively bonded joints using M5P and M5 classifiers

“…Ayatollahi predicted failure load of single-lap adhesive joints with various overlap length [12]. Ayaz et al [13] used adhesive bonding for repairing of the small damages in steel pipes subjected to internal pressure using composite patches and investigated the effect of overlap length and overlap angle by using the finite element method. Çitil et al [14] investigated the effects of patch thickness, overlap length, adherent thickness, and gap length of adhesively bonded double strap aluminum joints with and without intermediate part subjected to tensile loading by using finite element method.…”