The flexural properties of composite repaired pipeline: Numerical simulation and experimental validation

The performance of steel riser repaired with fibre reinforced polymer composite (FRPC) subjected to bending load was evaluated. Finite element (FE) analysis was used to simulate the load-strain behaviour of the repaired system. Accuracy of the model was validated against a simplified four-point bending experiment which was scaled to a significantly smaller size. The parameters investigated within the FE simulation and experimental tests are based on three conditions of the pipe riser - uncorroded, corroded and corroded repaired with designated laminate orientation of carbon/epoxy (C/E) FRPC. Design conditions were determined via a limit analysis known as the double-elastic slope method. The developed FE models based on flexural stiffness was found capable of predicting the same trend of strength improvements as the scaled-down testing of the corroded pipes repaired with different laminate orientation.