0385081 - ÚFM 2013 RIV GB eng J - Článek v odborném periodiku
Ševčík, Martin - Hutař, Pavel - Náhlík, Luboš - Lach, R. - Knésl, Zdeněk - Grellmann, W.
Crack propagation in a welded polyolefin pipe.
International Journal of Structural Integrity. Roč. 3, č. 2 (2012), s. 148. ISSN 1757-9864. E-ISSN 1757-9872
Grant CEP: GA ČR GC101/09/J027
Institucionální podpora: RVO:68081723
Klíčová slova: polymers * pipes * butt weld * crack
Kód oboru RIV: JL - Únava materiálu a lomová mechanika
DOI: https://doi.org/10.1108/17579861211235174

The purpose of this paper is to study the effect of the material inhomogeneity on crack behavior initiated both axially and circumferentially in or near the butt weld and to discuss consequences on residual lifetime of the welded structure. A three-dimensional numerical model of pipe weld with smooth and continuous change of material properties has been used to study the fracture behavior of the cracked pipe structure. The stress intensity factor was considered as a parameter controlling the fracture behavior. The semi-elliptical shape of the crack front was estimated under assumption of constant stress intensity factor along the crack front. According to the results obtained in the paper the following conclusions were deduced. First, the most critical location of the crack is in the middle of the inhomogeneous region (weld center) regardless of the crack orientation. The stress intensity factor is substantially higher than in the case of a crack located in the homogenous pipe. Second, with regard to crack shapes, the circumferentially oriented cracks are practically identical regardless to the crack location if compared with the axial cracks. Third, the stress intensity factors of axially-oriented cracks are approximately twice higher than in the case of circumferential cracks. This implies that the cracks are more likely to grow in an axial direction.
Trvalý link: http://hdl.handle.net/11104/0214475