Local Buckling Characteristics of Stainless-Steel Polypropylene Deep-Sea Sandwich Pipe under Axial Tension and External Pressure

Jianxing Yu,Mengxue Han,Shengbo Xu,Nianzhong Chen,Weipeng Xu,Sixuan Jiang

doi:10.3390/en14164866

Abstract

In this paper, the effects of different loading paths of axial tension and external pressure on the collapse pressure of sandwich tubes are studied by experiments and finite element models. The difference of the two loading paths is investigated. Eight experiments were carried out to study the influence of different loading paths on pipeline collapse pressure under the same geometric and material parameters. Parameterization studies have been carried out, and the results are in good agreement with the experimental results. The test and finite element results show that the loading path of external pressure first and then the axial tension (P→T) is more dangerous; the collapse pressure of the sandwich pipe is smaller than the other. Through parametric analysis, the influence of the axial tension and the diameter-to-thickness ratio of the inner and outer pipe on the collapse pressure under different loading paths are studied.

Highlights

With the shortage of onshore oil and gas resources, marine engineering has gradually received attention [1]
The finite element model is in good agreement with the experimental results of the sandwich pipe under external pressure and axial tension
This paper studies the influence of the two loading paths on the collapse pressure of the sandwich pipe, analyzes the point where the yield concentration occurs in the section, and explains the reasons for the difference

Summary

Introduction

With the shortage of onshore oil and gas resources, marine engineering has gradually received attention [1]. Risers mainly bear the combined action of external water pressure and axial tension, while pipelines are subject to external pressure, axial tension, bending moment, transverse loading, and torque [2,3,4,5,6,7,8]. The ultimate bearing capacity of the sandwich pipe will be reduced under the action of tension loads, which will cause local instability of the pipe. Due to the limitation of the experiment equipment, most of the tests apply the tension load first, and apply the external water pressure to study the ultimate bearing capacity of the pipeline. The loading sequence of external water pressure and axial tension has a great impact on the ultimate bearing capacity of the sandwich pipe. It is necessary to study the influence of different loading paths on the bearing capacity of the sandwich pipe

Results

Discussion

Conclusion