Influence of ageing in the failure pressure of a GFRP pipe used in oil industry. (January 2017)

• Record Type: Journal Article
• Authors: Reis, J.M.L.; Martins, F.D.F.; da Costa Mattos, H.S.
• Is Part Of: Engineering failure analysis. Volume 71(2017)
• Page Start: 120
• Page End: 130
• Publication Date: 2017-01
• Subjects: GFRP composite pipe -- Ageing -- Failure pressure -- Monotonic burst test -- Analytical modelling; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2016.06.013
• Languages: English
• ISSNs: 1350-6307

Abstract

Abstract: This paper is concerned with the influence of ageing in the failure pressure of a glass fibre reinforced polymer (GFRP) pipes used for oil and gas transport. Burst tests were performed on pipes submitted to accelerated ageing combining hydraulic pressure and temperature (1 MPa and 80 °C). An alternative method, which does not require the immersion in a water bath or other fluid bath, was adopted for the ageing of the specimens. The experiments show that the burst pressure can be strongly affected by the ageing period. Tensile tests also have been performed, showing a brittle-elastic behaviour. For this particular composite, the stiffness of the tensile specimen is not significantly affected by the ageing time, but the ultimate tensile stress (UTS) is affected by the ageing time. A methodology to obtain analytic estimates of both UTS and failure pressure for a given ageing time is proposed. In order to obtain a lower bound of the failure pressure at a given operation time, besides the pipe geometry, it is only necessary to know the UTS of the composite obtained in a minimum of three tensile tests performed at different ageing times. The prediction error is less than 0.8% for the UTS and is less than 25% for the failure pressure. Graphical abstract: Highlights: A new method for the ageing of GRFP hydrostatic test specimens is presented. Experiments show that the failure pressure of a GRFP pipe is affected by ageing. A simplified methodology to estimate the failure pressure of aged pipes is proposed. The methodology, adequate for thin-walled pipes, does not require hydrostatic tests. Only tensile tests performed at three different ageing times are necessary.