Parametric study for confined collapse of unbonded multi-layer pipe

ABSTRACT

If damage exists on the outer layer of an unbonded multi-layer pipe, the external hydrostatic pressure will be applied on the surface of the internal layer, most likely resulting in a confined collapse. This collapse response has been preliminarily investigated in previous research mainly considering the effects of various confinements and the diameter to thickness ratio of the internal layer. This paper begins with supplementary experimental studies to further discuss the result of former theoretical research. Then, parametric studies are undertaken to determine the effects of initial imperfection and friction. The modelling methods are selected to introduce different initial imperfections without other interference factors. It is shown that critical external pressure depends on the related parameters at different levels. The conclusions can be useful references for the design of the unbonded multi-layer pipe.

KEYWORDS:

• Unbonded multi-layer pipe
• confined collapse
• experimental study
• parametric study

Acknowledgements

The authors would like to acknowledge Kevin Conroy who seriously help us to examine the grammar of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Shuai Yuan http://orcid.org/0000-0001-7679-2428