Mechanical Analysis of Elastomer Seal in Subsea Pipeline Plugging Robot

To address the urgent demands of emergency repair following subsea pipeline leaks, pipeline isolation technology has emerged as a key development direction for subsea intervention systems. As the core functional component of subsea pipeline plugging robot, elastomer seal plays a critical role in both setting reliability and sealing performance. This study first reviews the typical operational workflow of subsea pipeline plugging robot and elucidates the “self energisation” mechanism of elastomer seal under high-pressure internal fluids. On this basis, a mechanical model of elastomer seal is formulated, and a theoretical expression for the contact stress between Elastomer seal and the pipe wall was derived. Five commonly used hyperelastic constitutive models are then examined, and their strain-energy functions and engineering stress expressions under uniaxial tension are systematically derived to provide a theoretical basis for rubber-material parameter identification. Subsequently, numerical simulations of elastomer seal’s sealing behavior under the hydraulic actuation system are performed in ABAQUS, followed by pressure-penetration-based analyses of the contact stress distribution under the combined action of the setting load and internal fluid pressure. Comparison between theoretical predictions and finite-element results enables further refinement of the contact stress formula, allowing the corrected model to more accurately predict elastomer seal sealing performance under hydraulic driving. The findings provide a reliable analytical framework to support the structural optimization and engineering design of subsea pipeline isolation devices.