Rapid Crack Propagation along Pressurized PE Pipe - Small Scale Testing and Numerical Modelling [PE]

Fracture & Resistance # 1992 Eindhoven

The small-scale 'S4' test for rapid crack propagation seems set to acquire the status of a specifying standard for polyethylene gas distribution pipe. This paper describes parallel research projects on pressureinstrumented S 4 t e s t s a n d on Finite-Volume numerical analysis of S4 and full-scale tests. whose objective is the prediction of full-scale critical pressure from S 4 tests or directly from material properties.

Please note that the whole article content is available on PPCA website onlySource : 1992 Eindhoven


Related papers

S4 to full-scale test correlation: new insights from an ‘open source’ RCP model

Author(s) : Patrick Leevers, Christos Argyrakis 2010 Vancouver

There is renewed interest in the correlation between critical pressures from lab-scale (S4) and full-scale RCP tests. The standard, supposedly material-independent correlation factor does provide a lower bound for data from many PE grades, but for some grades it is overconservative and for PA12 its applicability has...

Towards a methodology for designing RCP-resistant polyethylenes using batch scale test methods

Author(s) : P.Leevers 2010 Vancouver

This paper outlines a PE100 design methodology which gives central importance to the separate modelling and measurement of plane-strain and plane-stress dynamic fracture resistance. The former is difficult to measure but can be estimated from weight-average molecular weight; the latter is related to high-rate...

Rapid Crack Propagation Failures in HDPE Pipes; Structure-Property Investigations

Author(s) : Krishnaswamy, Leevers, Lamborn, Sukhadia, Register, Maeger 2006 Washington DC

The influence of molecular architecture on the rapid crack propagation (RCP) resistance of a wide variety of high-density polyethylene (HDPE) pipes was investigated. It was concluded that high molecular weight, high crystallinity and a relatively narrow molecular weight distribution are important architectural...

Rapid Crack Propagation in Loosely Fitted PE Liner Pipe

Author(s) : Leevers, Henderson, Pereira 2006 Washington DC

Laboratory-scale S4 tests have been used to determine whether it would be possible, at any realistic working pressure, for a loosely-fitted PE liner within a rigid host pipe to fail by Rapid Crack Propagation (RCP). The standard ISO 13477 S4 method was modified by replacement of the containment ring cage by a rigid,...

S4 Critical Pressure and Critical Temperature

Author(s) : Maeger, Vanspeybroeck, Lamborn, Mamoun, Leevers, Oliphant 2006 Washington DC

As polyethylene pressure pipes enter the global marketplace under an ever-wider range of operating conditions, there is increasing emphasis on their rapid crack propagation performance. It is important that both producers and end-users are able to rely on the robustness of the rapid crack propagation test results and...

Damage evolution and failure mechanisms in polyethylene

Author(s) : SKM Ting, JG Williams and A Ivankovic 2004 Milan

Recent experimental data (Ting et al (1-2) and Ting (3)) has shown that the onset and subsequent evolution of the damage (craze) was found to be sensitive to constraint effects, in addition to rates. In particular, the effect of notch depth was found to exert a greater influence on the material response than through...

S4 CRITICAL TEMPERATURE TESTS: PROCEDURE AND INTERPRETATION

Author(s) : Patrick Leevers 2004 Milan

International Standard ISO 13477 defines the ‘S4’ RCP test itself, and specifies two procedures which use it. The first procedure, already well embedded in referring standards, evaluates a critical pressure at constant temperature (usually 0°C) below which RCP arrests. The second procedure evaluates, at constant...

Fully Predictive Model of RCP in Plastics Pipes

Author(s) : Ivankovic, Tropsa, Jasak, Leevers 2001 Munich

This work presents a 3D coupled solid-fluid model for predicting fast failures in pressurised plastic pipes. It is developed within a unified computational procedure where both solid pipe and pressurising media are discretised using the Finite Volume method. The coupling is achieved across the pipe-fluid interface...

The Ductile-Brittle Transition in Pipe-Grade PE

Author(s) : Leevers, Moreno, Paizis 2001 Munich

The resistance of PE pipes to rapid crack propagation depends strongly on temperature. The critical pressure measured using ISO 13477 ‘S4’ tests increases abruptly above a transition temperature Tc. For PE100 grades Tc has become a primary index of quality : it must remain below 0°C despite a tendency to...

Ductile deformation in Pipe Grade PE

Author(s) : Hillmansen, Davis, Leevers 1998 Gothenburg

Rapid Crack Propagation in PE-100 gas pipes is governed primarily by a brittle-tough transition temperature TBT,above which ductile deformation will absorb energy and promptly arrest a fast-running brittle crack. Even at low temperatures, a layer of plastically deformed material is formed at the pipe bore during...

Fast brittle fracture of gas pressurised plastic pipes

Author(s) : Venizelos, Greenshields, Ivankovic 1998 Gothenburg

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...

Impact Rate and Geometry Effects in Pipe Grade Materials

Author(s) : Douglas, Leevers 1998 Gothenburg

A model for dynamic and impact fracture has been recently proposed whereby the fracture event is controlled by adiabatic heating and subsequent melting of the cohesive crack tip craze. The crack initiation resistance is shown to be an inherent function of specimen geometry and impact speed. This theoretical framework...

Process and Property Interactions in PE Pipelines

Author(s) : Davis, Greenshields, Dabas, Leevers 1998 Gothenburg

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...

Rapid Crack Propagation

Author(s) : Leevers 1998 Gothenburg

The international standardisation of tests for Rapid Crack Propagation (RCP) is approaching completion, and requirements for product and systems standards x e well established. Yet some basic issues about RCP remain contentious. In contrast to slow crack growth, there is a near-absence of service failure data, and in...

Rapid Extension and Failure of PE Craze Material

Author(s) : Hazra, Leevers 1998 Gothenburg

In previous work on the impact behaviour of pipe grade polyethylene (PE), the 'thermal decohesion model' was proposed by Leevers [ l ] to explain the embrittlement of PE under impact and at low temperatures. One of the initial assumptions of the model was that the crack tip craze could be represented by a Dugdale...

An analytical model of the gas discharge process in the S4

Author(s) : Venizelov, Greenshields, Leevers 1995 Edinburgh

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...

Fast fracture of plastic water pipes and the measurement of dynamic

Author(s) : Greenshields, Leevers 1995 Edinburgh

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...

Material, structural and pressurising fluid models for RCP tests on

Author(s) : Leevers, Greenshields, Venizelos, Ivankovic 1995 Edinburgh

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...

The effect of pressurizing fluid on fast fracture in plastic pipes

Author(s) : Greenshiels, Leevers 1995 Edinburgh

The failure of a pipe by rapid crack propagation (RCP) can, by its nature, be highly desmctive and must be avoided. Research over the past ten years has concentrated on gas pressurised pipelines and has resulted in a greater awareness and understanding of the problem. Recent attention has focused on RCP in...

Members of the Association

BOREALISBOROUGEINEOS O&PIRPCKorea Petrochemical IND. Co., LTDLyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
TOP