Van der Stok, Scholten
Papers # 2012 Barcelona
The Strain Hardening (SH) test developed by Kurelec et al. has been applied to a variety of PE pipe and resin materials. The clear trend in the strain hardening modulus, of first, second and third generation PE pipe resins and PE100 RC pipe resins, illustrates the large progress in resin quality during the past four decades. Next, a Round Robin test on a PE100 RC, PE100 and PE80 material was set up. The results obtained by eight labs are reproducible. This illustrates that the SH test is very promising to assess the resistance to slow crack growth of a wide range of PE pipe materials in a short-term experiment and in a reproducible manner.
SH tests were also performed on five pipe materials selected from the GERG (European Gas Research Group) Materials Bank and compared to their previously published FNC, Cone and Notch test results.
Tentative results of SH tests on another semi-crystalline polymer (Polyoxymethylene - POM) were obtained. Since the results of the SH test are determined by the intrinsic material properties, the test parameters used for PE cannot simply be copied.
