A fracture mechanics assessment of surface cracks existing in protective layers of multi-layer composite pipes

0353692 - ÚFM 2011 RIV GB eng J - Journal Article
Hutař, Pavel - Náhlík, Luboš - Šestáková, Lucie - Ševčík, Martin - Knésl, Zdeněk - Nezbedová, E.
A fracture mechanics assessment of surface cracks existing in protective layers of multi-layer composite pipes.
Composite Structures. Roč. 92, č. 5 (2010), s. 1120-1125. ISSN 0263-8223. E-ISSN 1879-1085
R&D Projects: GA ČR GA106/09/0279
Institutional research plan: CEZ:AV0Z20410507
Keywords : Protective layers * Multi-layer pipes damage * Fracture mechanics * Bi-material interface * Generalized stress intensity factor
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 2.028, year: 2010

The influence of a cracked protective layer on the integrity of composite multi-layer pipes is analyzed in this paper. The multi-layer pipe is modeled as a particular case of a bi-material body consisting of two different homogeneous materials. The problem is studied under assumptions corresponding to small scale yielding conditions and ideal adhesion between protective and main layers is assumed. The case of a crack with its tip at the interface between protective and main layers is analyzed in detail and the influence of the material composition on the corresponding critical pressure for a brittle-like failure is discussed. An approximate approach based on estimation of crack mouth opening displacement for thin protective layers is suggested. The results have been applied to study the scratch resistance of multi-layered plastic pipes.
Permanent Link: http://hdl.handle.net/11104/0192862