Mechanical behavior of pipe reinforced by steel wires under external pressure

Abstract

Plastic pipe reinforced by helically cross-winding steel wire (namely PSP) is a novel kind of composite pipe which consists of an inner high-density polyethylene layer, steel wire layers and an outer polyethylene coating. PSP has the potential application as subsea pipeline. Based on numerical 2D ring model, proposed by Yong Bai, the wall thickness change, transverse shear deformation and pre-buckling deformation have been considered in the collapse investigation of PSP under external hydrostatic pressure. Based on finite element method, reinforced layers were taken as transverse isotropic material, and equivalent elastic modulus was obtained based on Halpin–Tsai model. It is shown that steel wires layer has little effect (just 0.2% difference) on the behavior of PSP under external pressure. The external pressure–ellipticity and external pressure–hoop strain curves derived from the theoretical method and finite element method are compared and show a good agreement (deviation of buckling pressure is 1.4%). Finally, maximum experimental external pressure values of two pipe specimens were obtained by increasing hydrostatic pressure in a closed cylinder. The results of theoretical analysis and finite element method are in great agreement with the experimental values.

Keywords

Steel wire composite pipe mechanical behavior theoretical analysis finite element method external hydrostatic pressure experiments

Get full access to this article

View all access options for this article.

References

Chen

Seemann

Krause

. Prototyping and testing of composite riser joints for deepwater application. J Reinf Plast Compos. 2016; 35: 95–110..

Zheng

. Experimental investigation on mechanical properties of plastic pipes reinforced by cross helically steel wires. J Pressure Vessel Technol 2008; 130: 021401–021401.

Sridharan

Kasagi

. On the buckling and collapse of moderately thick composite cylinders under hydrostatic pressure. Compos B Eng 1997; 28: 583–596.

Sato

Patel

. Exact and simplified estimations for elastic buckling pressures of structural pipe-in-pipe cross sections under external hydrostatic pressure. J Mar Sci Technol 2007; 12: 251–262.

Arjomandi

Taheri

. Elastic buckling capacity of bonded and unbonded sandwich pipes under external hydrostatic pressure. J Mech Mater Struct 2010; 12: 391–408.

Arjomandi

Taheri

. A new look at the external pressure capacity of sandwich pipes. Mar Struct 2011; 24: 23–42.

Corona

Rodrigues

. Bending of long cross-ply composite circular cylinders. Compos Eng 1995; 5: 163–182.

Corona

Kyriakides

. Asymmetric collapse modes of pipes under combined bending and external pressure. J Eng Mech 2000; 126: 1232–1239.

Cheng P. In-plane nonlinear theory and elastic-plastic stability of pined circular arches. PhD Thesis, Zhejiang University, China, 2005.

10.

Gong

Sun

Bao

. Buckle propagation of offshore pipelines under external pressure. Mar Struct 2012; 29: 115–130.

11.

Gong

Yuan

. Buckling response of offshore pipelines under combined tension and bending. Struct Eng Mech 2012; 41: 805–822.

12.

Bai Y, Wang NS and Cheng P. Collapse of RTP (reinforced thermoplastic pipe) subjected to external pressure. In: ICPTT: better pipeline infrastructure for a better life. Reston, VA: ASME, 2013, pp.725–743.

13.

Ashraf

Morozov

Shankar

. Flexure analysis of spoolable reinforced thermoplastic pipes for offshore oil and gas applications. J Reinf Plast Compos 2014; 33: 533–542.

14.

Gellin

. The plastic buckling of long cylindrical shells under pure bending. Int J Solids Struct 1980; 16: 397–407.