Numerical Investigation of Lateral Buckling in Fluid-Conveying Pipes

Abstract

Subsea pipes for offshore oil and gas operations face the risk of flow-induced lateral buckling failures. This study implements a one-way coupled computational fluid dynamics (CFD) and finite element analysis (FEA) approach to evaluate the fluid-structure interaction effects on pipe buckling behavior. The model consists of a 6m long, 0.5m diameter steel pipe subjected to varied internal flow velocities, axial loads, pipe thicknesses, operating pressures and temperatures. The findings demonstrate that internal pressure has the most significant impact, with critical buckling pressure doubling from 3.1 bar to 6.8 bar for a pipe thickness increase from 5mm to 20mm. Axial loads of 0 to 40 MPa reduced the critical velocity by 2.5 m/s. Gradual effects were seen for diameter and temperatures changes. The post-buckling response reveals single wavelength sinusoidal deformation shapes, with displacements amplifying exponentially beyond critical velocities. At 3 m/s over the threshold, pipe deflections reached 0.35m. The model effectively quantifies stability limits to guide subsea pipe design.