On crack propagation in the welded polyolefin pipes with and without the presence of weld beads

0451977 - ÚFM 2016 RIV GB eng J - Journal Article
Mikula, Jakub - Hutař, Pavel - Nezbedová, E. - Lach, R. - Arbeiter, F. - Ševčík, Martin - Pinter, G. - Grellmann, W. - Náhlík, Luboš
On crack propagation in the welded polyolefin pipes with and without the presence of weld beads.
Materials and Design. Roč. 87, DEC (2015), s. 95-104. ISSN 0264-1275. E-ISSN 1873-4197
R&D Projects: GA ČR(CZ) GAP108/12/1560; GA MŠMT(CZ) EE2.3.30.0063; GA MŠMT(CZ) ED1.1.00/02.0068
Institutional support: RVO:68081723
Keywords : Slow crack growth * Butt weld * Lifetime estimation * Polyolefin pipes * Weld bead
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 3.997, year: 2015

The main aim of the paper is to study the influence of both material inhomogeneity and weld bead geometry on crack propagation in welded polyolefin pipes. Axially and circumferentially oriented cracks are studied and the stress intensity factors are compared considering different positions of the cracks. Two cases of the welded pipe system are compared, one considering the optimal weld bead geometry and the other one considering the geometry after removing the weld bead once the welding process is finished. In both cases the inhomogeneous distribution of material properties inside the welded region is considered. The results show that the weld might have a negative effect on the lifetime especially when the weld bead is removed. Though the weld bead increases the stress concentration near the notches due to which a circumferential crack may appear the resulting lifetime is still comparable to that of an axial crack propagating in a homogeneous pipe.
Permanent Link: http://hdl.handle.net/11104/0253177