Phenomenological modelling of tensile fracture in PE pipe by considering damage evolution

摘要

Tensile fracture of polyethylene (PE) pipe in the hoop direction has been investigated using a phenomenon-based, hybrid approach of combining experimental testing and FE simulation. A modified D-split test was used for the experimental testing, at three crosshead speeds of 0.01,1, and 100 mm/min. The test results were then used to establish the governing equation for the specimen deformation so that the FE model can regenerate the data obtained from the experimental testing. Two approaches were considered for the FE simulation, one with separate expressions for deformation and damage evolution, and the other without. Results from the FE simulation suggest that the former approach enables the FE model to simulate both large deformation and ductile fracture of the test, while the latter can only mimic the large deformation before the final stress drop. Although the expression established in this study is unlikely to be unique for the damage evolution, it provides a qualitative means to depict the damage evolution during the test. Using parameters in the expression for damage evolution as variables, with the stress-strain relationship fixed, the FE simulation provides results to characterize the influence of damage evolution rate on the load-stroke curve generated from the D-split test.