External surface cracked offshore pipes reinforced with composite repair system: A numerical analysis. (February 2022)

• Record Type: Journal Article
• Authors: Li, Zongchen; Jiang, Xiaoli; Hopman, Hans
• Is Part Of: Theoretical and applied fracture mechanics. Volume 117(2022)
• Publication Date: 2022-02
• Subjects: Surface crack growth -- Finite element method -- Composite repair system -- Stress intensity factor -- FRP-to-steel interfacial bond condition; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2021.103191
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: Finite element analysis on the surface crack growth in steel pipes reinforced with CRS. The FE model is validated by the experimental results. Based on the FE model and Paris' law, surface crack growth rate is quantitatively evaluated. Revealing the mechanism of CRS reinforcement on the surface cracked steel pipes. Indicating the key influential parameters of CRS reinforcement on surface cracked steel pipe. Abstract: This paper conducts a numerical analysis on the external surface cracked steel pipes reinforced with Composite Repair System. A three-dimensional finite element (FE) model is developed to calculate the Stress Intensity Factor (SIF) of the surface crack, and the crack growth process is evaluated by the Paris' law. The effect of FRP-to-steel interfacial bond condition on the SIF evaluation has been considered by incorporating the cohesive zone modelling. Then the FE model is validated by the experimental results. Thereafter, major issues including "interfacial bond condition" and "reinforcement effectiveness and influential parameters" have been discussed. The results indicate the reinforcement effectiveness on reducing the SIF owes to the decreasing of stress magnitude and the crack-bridging effect. Because of the crack-bridging effect, composite reinforcement performs more efficiently on reducing the SIF at the surface point than at the deepest point of the surface crack. The negative influence of the FRP-to-steel bond condition on the surface crack growth is not as significant as on reinforcing through-thickness cracks. However, since the interfacial stiffness is sensitive to the adhesive thickness, choosing an ideal adhesive thickness to acquire a good reinforcement effectiveness and to avoid potential interfacial bond failures is recommended.