Our site uses cookies necessary for its proper functioning. To improve your experience, other cookies may be used: you can choose to disable them. This can be changed at any time via the Cookies link at the bottom of the page.


FINITE ELEMENT METHOD (FEM) USED TO SIMULATE THE STRESS/STRAIN OF THE POINT LOAD TEST (PLT) IN A BROADER STUDY TO SUPPORT THE FUTURE ISO TEST STANDARD

 

S. Nestelberger, J. Cheng

# 2021 Amsterdam

The Point Load Test (PLT) [‎ 1, ‎ 2] was designed to simulate the SCG (slow crack growth) failure initiated by a rock pressing into the exterior wall of a polymer pipe. Today’s PE materials sustain long PLT testing times, due to its high SCG resistance design. Consequently, an accelerated “PLT+” with the support of enhanced detergents and higher temperatures was introduced [‎ 3].

Unexpectedly, discrepancies between failure modes of 32mm vs. 110mm PE pipes in the PLT+ method is noticed. The study examines possible root causes of noticed discrepancies via applied Finite Element Methods (FEM), focusing on the effects of different material models (elastic, elasto-plastic) and different pipe geometries. Considering those effects in the Finite Element simulations opens an unique possibilityfor detailed analysis of stress/strain fields close to the relevant regions of fracture of pipe material. Different pipe sizes clearly show distinct deformation states at the location of the point load. Either the deformation is more compression or lateral bending dominated. The computed deformations states as well as the computed stress concentration locations fit very well the observed locations of crack initiation zones in laboratory tests.

Related keywords : PE100-RC, Point load test, PLT, slow crack growth, FEM simulation, Polyethylene pipe, trenchless installation.
Please note that the whole article content is available on PPCA website only


Related papers

2021 Amsterdam : A NEW GENERATION OF HIGH PERFORMANCE BIAXIALLY ORIENTED POLYETHYLENE AND POLYPROPYLENE PRESSURE PIPES

Author(s) : A. Taraiya, P. Degenhart, M. Soliman, M. Boerakker, R. Handstanger, R. Kleppinger

Since the introduction of polyolefins for pressure pipes, continuous improvements have been made to meet ever-higher demands on their performance and to expand their application window beyond their original scope, mostly based on new resin formulations. Today, we also continue to push the limit to provide better...

2021 Amsterdam : A TRADE ASSOCIATION EXPLORED

Author(s) : Drew Mueller, Peter Dyke

HDPE Pipe holds a dominant position in several markets in North America: natural gas distribution, oil patch, mining, landfill and geothermal. So why are polyethylene’s municipal water and wastewater market shares so much lower than these other industries? How has the polyethylene industry been successful in growing...

2021 Amsterdam : AN EVIDENTIAL APPROACH TO USE OF POLYETHYLENE PIPE FOR HYDROGEN FUEL GASES

Author(s) : Derek Muckle

A technical program has been undertaken to provide evidence on the suitability of polyethylene pipe and fitting systems for the distribution of hydrogen fuel gas. The underlying principle has been to evaluate material in the form of a pipe and to consider the performance of the pipe and of the welded jointing systems...

2021 Amsterdam : APPLICATION OF PP-R COMPOSITE REINFORCED PIPES IN HOT AND COLD WATER SYSTEMS

Author(s) : Lei Wang, Guozhi Xu, Qiaoping Qiu, Weihua Lu, Yanwang Han

PP-R (random copolymerized polypropylene) has been widely used in hot and cold water systems. However, the standard PP-R pipes have the disadvantages of a large high-temperature thermal expansion coefficient, an insufficient notched impact strength, and a low temperature and pressure resistance. In this paper, a new...

2021 Amsterdam : CHALLENGING THE 10% WALL THICKNESS RULE FOR HDPE MARINE PIPELINES

Author(s) : Ilija Radeljic, Ebbe Smith

HDPE pipe can be relatively easily scratched during the manipulation on the site, which is especially true for the marine pipelines. Installing the scratched marine pipe with the S bend method presents a risk and repair methods are usually performed. Currently, there is no standard defining the repair procedure, in...

2021 Amsterdam : DESIGN OF A DISTRIBUTED STRAIN MONITORING SYSTEM FOR HDPE WATER PIPELINES CROSSING AN EARTHQUAKE FAULT

Author(s) : Peter Hubbard, Linqing Luo, Andrew Yeskoo, Kenichi Soga, Krista (Moita) Araica, Gus Cicala, Marshall McLeod

Seismically active faults pose a risk to buried water pipelines that can be complicated to quantify. Fault type, slip rate, pipeline geometry, and soil conditions all factor into a complex soil-pipeline interaction. For critical pipelines that cross faults, high-density polyethylene (HDPE) has become an attractive...

2021 Amsterdam : DESIGN OF LARGE DIAMETER BURIED PIPES

Author(s) : Anders Andtbacka, Peter Sejersen

In the late nineties a study of the behavior of buried thermoplastics pipes was carried out. The project had input and participants from both the plastic pipe industry as well as from external organizations. Six external leading experts in the field of pipeline design, not necessarily plastics pipes design, have been...

2021 Amsterdam : DEVELOPMENT OF A RAPID AND INNOVATIVE IN-FACTORY PROCEDURE FOR TESTING THE PERFORMANCES OF PE PIPES CONTAINING VARIOUS PROPORTIONS OF RECYCLED POLYMER MATERIAL

Author(s) : Dominique GUEUGNAUT, Pascal AUSSANT, Romuald BOUAFFRE, Myriam BECHROURI

Concerns regarding the environment and sustainable development have revived interest in the reprocessing and re-use of polymer materials from manufactured objects that have reached the end of their operating life. Within this framework, formal professional agreements have been put in place at global level under the...

2021 Amsterdam : EFFECT OF CHLORINATED WATER ON THE FATIGUE CRACK GROWTH RESISTANCE OF POLYETHYLENE COMPOUNDS WITH RECYCLATE CONTENT FOR PIPE APPLICATIONS

Author(s) : Paul J. Freudenthaler, Joerg Fischer, Mathias Eder, Reinhold W. Lang

For controlled water disinfection, typically chlorine is used and preliminary studies demonstrate its aging and crack growth acceleration effects on polyolefin pipe materials [1, 2]. Although the use of recycled plastics is not prohibited in some ISO standards for polyolefin piping systems [3–5], only small amounts...

2021 Amsterdam : EFFECT OF INSUFFICIENT HOMOGENIZATION DURING THE EXTRUSION OF POLYETHYLENE PIPES ON BUTT FUSION JOINT INTEGRITY

Author(s) : Mike Troughton, Amir Khamsehnezhad, Changyi Yu

When butt fusion welding polyethylene (PE) pipes in the field, it is often specified that the pipes must undergo fusibility testing in all combinations of suppliers, diameters and thicknesses before being fused in production. This is a very onerous and expensive task, but must be carried out to ensure that the PE...

2021 Amsterdam : EVALUATION OF MECHANICAL PROPERTIES AND LONG- TERM DURABILITY OF AGED POLYETHYLENE PIPES FOR GAS DISTRIBUTION

Author(s) : Shuhei Nishida, Shintaro Iwasaki, Hidefumi Yamanaka, Takahiro Kasatani

Polyethylene pipelines have been used for natural gas service applications for over 40 years in Japan. It is thought that they will continue to be used widely for many years. Therefore, it is important to confirm the conditions of the existing pipelines being used for the long term. In this study, polyethylene pipes...

2021 Amsterdam : EXPERIMENTAL DETERMINATION OF THE EFFECTS OF LIQUID HYDROCARBONS ON THE LONG-TERM CREEP RUPTURE PROPERTIES OF PRESSURE PIPE GRADE UNPLASTICIZED POLYAMIDE-12

Author(s) : James F. Mason, Akshay Ponda, Hermann van Laak, Buc Slay

The effects of liquid hydrocarbons on long term strength of pipe grade thermoplastic resins is an important consideration when designing pressure pipe for use in the oil and gas industry. There is an extensive body of work going back several decades descri bing these effects for pipe grade polyethylenes, and all...

2021 Amsterdam : FINDING THE RELATIONSHIP BETWEEN NON-DESTRUCTIVE TEST METHODS AND THE TENSILE IMPACT TEST ON PVC PIPES

Author(s) : Sjoerd Jansma, René Hermkens

More than 20,000 km of rigid PVC (or PVC-U) pipes are currently in use for the distribution of natural gas in the Netherlands. In this decade, the majority of these pipes will reach their initially specified lifespan of 50 years. In the light of a possible replacement surge, it is increasingly important to identify...

2021 Amsterdam : FINDING THE RIGHT PIPE TEST FOR POLYETHYLENE WITH RAISED RESISTANCE TO SLOW CRACK GROWTH

Author(s) : Ernst van der Stok

For PE 100-RC, two tests are still under development for pipes: the point load test (PLT) and the accelerated notch pipe test (aNPT). The PLT was developed by a project group consisting of manufacturers and end users. The PLT determines the resistance to point loads as they can occur in practice. An earlier study...

2021 Amsterdam : FIRST USE OF PE100-HT CONDUITS FOR ADVANCING THE CONTAINMENT OF UNDERGROUND HIGH VOLTAGE CABLES

Author(s) : Dr. Holger Brüning, Serge Hascoët, Yann Delanne, Didier Nozahic, Jawdat Mansour, José Santana

RTE operates, maintains and develops the French electricity network, including the High and very High Voltage cable lines. Their network is the largest in Europe and includes over 6400 km of underground HV links operated in 2018. The company is modernizing and developing its network by investing 1.5 billion euros per...

2021 Amsterdam : FLOWABLE FILL FOR PLASTIC PIPE

Author(s) : Amster Howard

Flowable fill is used for many applications, but mainly for pipe trench embedment and backfill. There are three ways that using flowable fill can be kind to the environment. Because flowable fill is self-leveling and has a strength greater than the native soil, the trench cross section can be minimized. This means...

2021 Amsterdam : FROM MULTILAYER LAMINATES TO INDUSTRIAL PIPE APPLICATIONS – A GUIDELINE

Author(s) : Gerald Pinter, Johannes Wiener, Florian Arbeiter, Abhishek Tiwari, Otmar Kolednik

For pipe applications, catastrophic failure due to crack growth has to be prevented by all means. Techniques to develop new and even tougher pipe materials are explored in this contribution. The aim is to create a multi-layer architecture, that exhibits high toughness as well as damage tolerance towards sharp notches....

2021 Amsterdam : GROWTH IN THE USE OF POLYETHYLENE PIPES IN MEA FOR NATURAL GAS UTILITY DISTRIBUTION

Author(s) : Sultan Alkendi, Mohamed Jaber, Ahmed Atef Helal

The current push to reduce governmental energy subsidies has moved the need to adapt utility gas distribution networks toward the top of Middle Eastern governmental near-term agendas. Egypt is at the forefront of this push towards gasification. The United Arab Emirates has started on the path towards gasification...

2021 Amsterdam : HYDROGEN TRANSPORT IN POLYMER PIPES FOR NATURAL GAS DISTRIBUTION – TEN YEARS OF EXPERIENCE

Author(s) : Stephan Kneck, Henrik Iskov

It has become ever clearer that the resources of natural gas are an energy source, which will be less important in the future due to limitations in use of natural reserves. In order to prepare for the future the gas industry is looking at the alternative fuel gases, one such fuel gas is hydrogen. In order to prepare...

2021 Amsterdam : INNOVATIVE MILLIMETER WAVE TECHNOLOGY FOR MEASURING THE PIPE WALL THICKNESS EARLY IN THE EXTRUSION PROCESS

Author(s) : Christian Schalich

Plastic pipes for infrastructure and building applications are precisely specified with regards to wall thickness and diameter. Pipe manufacturers use different measuring methods in order to ensure the required dimensional accuracy and maintain a constant high quality. This paper introduces a measuring system based on...

Members of the Association

BOREALISBOROUGEFormosa Plastics CorporationINEOS O&PIRPCKazanorgsintez PJSCKorea Petrochemical IND. Co., LTD (KPIC)LyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
Webinar : Benefits of PE100+ Material and their use in Trenchless TechnologyWebinar : Benefits of PE100+ Material and their use in Trenchless Technology

On march 10th, was held the PE 100+ ASSOCIATION first webinar. The webinar was a great success and attracted a large audience. 

TOP