Bruchmechanische Methoden zur beschleunigten Charakterisierung des langsamen Risswachstums von Polyethylen-Rohrwerkstoffen

Translated title of the contribution: Fracture mechanics methods for the accelerated characterization of the slow crack growth behavior of polyethylene pipe materials

Markus J. Haager

Research output: ThesisDoctoral Thesis

Abstract

The objective of this dissertation was, to investigate systematically and widespread different existing as well as new methods to characterize the slow crack growth (SCG) behavior of PE pipe materials. With every method a multitude of commercially available PE 80 as well as PE 100 types, were investigated. Besides determining their applicability and limitations it should also be evaluated which methods are capable of characterizing the SCG behavior of these materials accurately and with high acceleration. Initially the full notch creep test (FNCT) and static tests on compact type (CT) specimens were conducted. Moreover cyclic tests on CT specimens as well as on cracked round bar (CRB) specimens were performed to investigate quasi-brittle crack growth. It was found, that it was not possible with the applied static crack growth tests to characterize the SCG behavior of the investigated materials within practicable time frames. This improved applying fatigue loads to CT specimens, but this method proved incapable of detecting small differences between the materials. Finally the cyclic crack growth tests on CRB specimens turned out to be most suitable to characterize the crack growth behavior of PE pipe materials accurately and quickly. Because of the high potential of this type of fatigue test, it is intended to develop a methodology, that uses cyclic tests on CRB specimens to assess the lifetime of PE piping systems for arbitrary loading conditions.
Translated title of the contributionFracture mechanics methods for the accelerated characterization of the slow crack growth behavior of polyethylene pipe materials
Original languageGerman
Supervisors/Advisors
  • Lang, Reinhold, Assessor A (internal)
  • Lederer, Klaus, Assessor B (internal)
Publication statusPublished - 2006

Bibliographical note

embargoed until null

Keywords

  • Polyethylene Pipe Fracture Mechanics
  • Linear Elastic Slow Crack Growth Full Notch Creep Test Compact Type Cracked Round Bar

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