Effect of fabricating process and seawater temperature on radial compression and physical properties of filament-wound risers

Abstract

This study evaluates the impact of fabrication parameters on the mechanical and physical properties of filament-wound risers exposed to varying seawater conditions. Using a Box-Behnken design, three key process parameters including winding tension, winding speed, and curing time were selected for multiple sets of repeated experiments. The composite risers were immersed in seawater at 5°C, room temperature (RT), and 70°C for 4 months. After aging, their compressive performance was tested to investigate how the manufacturing parameters affected mechanical behavior, and micro-morphology was used to examine changes in resistance and damage. The results showed that the average peak compressive force (PCF) changed very little at 5°C and room temperature. But at 70°C, it dropped sharply by 23.8%. Specimens gained 1.8% mass at 5°C and RT due to moisture uptake but lost 8.8% at 70°C because metal-liner corrosion exceeded hygroscopic gain. Process optimization showed that a winding speed of 4 m/min and tension of 45 N consistently improved anti-aging performance across all conditions.