Failure pressure prediction of high-strength steel pipe bend considering pipe and corrosion geometry

Abstract

This study examines the influence of pipe bend geometry and corrosion geometry on the failure pressure of high-strength steel pipe bends subjected to internal pressure and axial compressive stress. Finite element analysis determines the impact of bend angle, bending radius, defect depth, defect length, defect spacing, and axial compressive stress on failure pressures. The findings reveal that increasing the bend angle reduces failure pressures significantly, with corrosion defects exacerbating this effect. Increased bending radius increases normalized failure pressure from 0.88 to 0.91 for intrados defects and decreases it from 0.98 to 0.93 for extrados defects. Additionally, single defects cause a slight 2.5–3.0% reduction in normalized failure pressure, while longitudinally and circumferentially aligned defects result in a 13–15% decrease in normalized failure pressure. Defect depth and length also significantly influence the failure pressure, particularly for deeper and longer defects (up to 48.2%). Furthermore, an empirical equation for predicting failure pressures in corroded pipe bends with high accuracy (R2 = 0.99) is developed based on Artificial Neural Network. This enhances pipeline integrity assessment and design practices.