Special fracture mechanics specimens for multilayer plastic pipes testing

0332041 - ÚFM 2010 RIV GB eng J - Journal Article
Hutař, Pavel - Šestáková, Lucie - Knésl, Zdeněk - Nezbedová, E. - Náhlík, Luboš
Special fracture mechanics specimens for multilayer plastic pipes testing.
Polymer Testing. Roč. 28, č. 8 (2009), s. 785-792. ISSN 0142-9418. E-ISSN 1873-2348
R&D Projects: GA ČR GA106/09/0279; GA ČR GC101/09/J027
Institutional research plan: CEZ:AV0Z20410507
Keywords : Multilayer plastic pipes * C-type specimen * K-calibration * Fracture toughness * Slow crack growth * Non-homogenous specimens
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 1.667, year: 2009

Pipes consisting of layers of different materials (multilayer pipes) are considered. The fracture toughness value of the main pipe is taken into account as a parameter relevant to fracture assessment connected with the resistance of pipe material against slow crack growth. With the aim of simplifying estimation of main pipe material fracture toughness, non-homogeneous test specimens cut directly from multi-layer pipes are suggested and numerically analysed. The values of the corresponding stress intensity factor KI and biaxiality factors B are calculated for the case of two and three layer test specimens. Based on the results obtained, the transferability of fracture toughness values measured on laboratory specimens to pipe systems is discussed. It is shown that in most cases of multilayer commercial pipes and routine fracture toughness measurements the values of the stress intensity factor calculated on the basis of homogeneous specimens can be used.
Permanent Link: http://hdl.handle.net/11104/0177397