Failure analysis of putty‑composite patch repair system for wall loss damaged pipelines

Wrapping glass fiber-reinforced polymer (GFRP) composites around damaged pipes are effective method and accepted in
practices. The main aim of this paper is to propose new composite repair geometry to optimize the wrap repair thickness for
cost-effective repair system using finite using finite element analysis (FEA). Two different repair geometries were considered:
one where the defect cavity was completely filled with putty (resin) material and a new proposed geometry where the cavity
was partially (50%) filled with putty and remaining with a GFRP patch. The numerical results show that using a 50% GFRP
patch above putty material in the defect cavity reduces the composite wrap thickness from 8.4 to 5.4 mm, decreasing material
usage by 40%. Replacing the GFRP sleeve with a high-strength carbon fiber composite further reduced the wrap thickness
from 5.4 mm to 1.6 mm but with additional material cost. Composite repair system demonstrated marginal improvement
of 6% rise, when the stiffness of putty material was increased from 3500 to 7000 MPa. This study highlights the potential
of tailored repair geometries for effective load transfer between pipe and composite wrap through putty composite patch to
reduce composite wrap material while maintaining repaired structural integrity. The proposed method offers a cost-effective
solution, particularly suitable for repairs in confined or restricted areas.