Fast small scale method to predict materials resistance to rapid crack propagation

The resistance of polyethylene (PE) pipes to rapid crack propagation (RCP) is normally tested using the small-scale steady-state test (S4). Even though the S4 test is a small scale test compared to the full scale test, it still requires a lot of material for pipe extrusion and the testing takes rather long time. There are fast small scale tests for RCP available, but we wanted to develop an easy and practical method for material screening to get a first idea of materials resistance to RCP. In this paper we introduce a fast small scale method where very light razor blade notched Charpy specimens are tested over a temperature range. The temperature where the first partial break occurs is taken as Charpy critical temperature (Tc). Good correlation between the Charpy critical temperature and the S4 critical temperature was found. By this way we can get an estimation of the S4 Tc already from the laboratory scale materials.