Numerical Simulations for the Mechanical Behavior of a Type-B Sleeve under Pipeline Suspension

Abstract

The type-B sleeve is widely used for reinforcing defective pipelines. Due to the impact of suspension on pipeline safety, the behavior of the type-B sleeve structure has garnered increasing attention. In this study, we establish a numerical model of a defective pipeline reinforced with a type-B sleeve while accounting for the effects of the internal natural gas pressure and gravitational load. We investigate the influence of the sleeve length, suspended pipeline length, internal pressure, and sleeve position on the mechanical behavior of the type-B sleeve. The maximum values for Mises stress and axial strain were both observed near the edge of the suspended segment of the pipeline. For the type-B sleeve structure, the high Mises stress zone was at the bottom of the fillet weld; the axial strain near the fillet weld alternated between tension and compression along the axial direction. With an increase in internal pressure and suspended pipeline length, the Mises stress and axial strain of the type-B sleeve became more prominent. For sleeve length in the ranges of 1 to 3 m, the changes in the stress and strain did not exceed 10 MPa and 0.5 × 10−3, respectively. However, the Mises stress and axial strain on the type-B sleeve structure were independent of the position of the defect on the pipeline. This study provides an important reference for type-B sleeve protection during suspension and other similar practical engineering applications.