[Zurück]

A Frank, M Messiha, T. Koch, J Poduska, P Hutar, F. Arbeiter, G. Pinter:
"Correlation of the cyclic cracked round bar test and hydrostatic pressure test for unplasticized polyvinylchloride";
Polymer Testing, 75 (2021), 107125; S. 1 - 7.

The applicability of the cracked round bar (CRB) test according ISO 18489 for the characterization of slow crack
growth (SCG) in unplasticized polyvinylchloride (PVC-U) was analyzed by testing three PVC-U pipe compounds
with different molecular mass, represented by different intrinsic viscosity numbers (K-values). The tests were
conducted at lower stress loading ranges than recommended by the standard. The SCG resistance showed a clear
dependency on the K-value resulting in a higher crack resistance with increasing K-value. Moreover, the results of
the CRB tests were correlated to hydrostatic pressure tests of PVC-U pipe grades with different K-values. A clear
linear correlation between the results of both methods was established, thereby demonstrating a significant
acceleration of testing times with the CRB test. With a special focus on EN 1401-1, it was elaborated that the
requested minimum failure resistance of 1′ 000 h in the hydrostatic pressure test at T = 60 ◦C correlates to 97′ 000
cycles, or 2.7 h, respectively, in the CRB test at T = 23 ◦C.

slow crack growth; fracture mechanisms; stress intensity factor; PVC-U; pipe material ranking

http://dx.doi.org/10.1016/j.polymertesting.2021.107125

https://publik.tuwien.ac.at/files/publik_295307.pdf