Greenshields
Additional Information - Posters # 1998 Gothenburg
Brittle failures in service water pipelines sometimes occur at relatively low pressures and for no apparent reason. This paper presents a review o f research into brittle fracture in water pipes and questions some o f the received assumptions which obscure tlie subject. The hydrostatic S4 test is proposed to measure the critical pressure in water pipes, above which brittle fracture can be sustained. The dynamic fracture tougliness o f the pipe material is calculated from a single critical pressure result using the lnvin-Corten analysis. The analysis can then be inverted to calculate tlie critical pressure o f any size o f pipe, providing the basis for design and operation o f a pipeline. Further experimental work investigates tlie effect o f pipe temperature and o f occluded air pockets on brittle fracture.
Related papers
Author(s) : Venizelos, Greenshields, Ivankovic
Over 30 years ago, fast brittle fracture was identified as an inherently catastrophic failure mode in pressurised plastic gas pipelines. Although fast cracks seemed difficult to initiate, subsequent rapid crack propagation (RCP) was thought to be possible at pressures lower than the rated pressure, imposed by design...
Author(s) : Davis, Greenshields, Dabas, Leevers
The study of Rapid Crack Propagation (RCP) in pressurised pipelines is of particular importancr to th? g a industry, where the possibility of such a failure must he minimised. Polyethylene (PE) currently dominates the market for plastic gas pipelines, and as the demands for larger diameters .and higher operating...
Author(s) : Venizelov, Greenshields, Leevers
An analytical I-D model of the gas discharge process in the small scale steady State ( ~ 4 ) test for rapid g a c k propagation (RCP) in thermoplastic pipe has been developed. Because the gas can exert a powerful crack driving force, such a model is essential to an understanding of the test. This model yields a...
Author(s) : Greenshields, Leevers
Previous research has concluded that rapid crack propagation (RCP) cannot be sustained in 100% water pressurised pipe. However, this paper shows that by reducing the decompression wave speed in water to below the crack speed, it is possible t o sustain fast cracks in thermoplastic pressure pipe. T h e prediction of R...
Author(s) : Leevers, Greenshields, Venizelos, Ivankovic
The development of pipe-grade materials to resist slow crack growth and ductile rupture has been spectacularly successful. It is a measure of this success that concern with Rapid Crack Propagation (RCP) has increased to the level evident at this conference. Stronger materials encourage the use of higher...
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