CHARPY AND DYNAMIC FRACTURE TESTING FOR RAPID CRACK-PROPAGATION IN POLYETHYLENE PIPE


LEEVERS P., YAYLA P. , WHEEL M.

PLASTICS RUBBER AND COMPOSITES PROCESSING AND APPLICATIONS, cilt.17, ss.247-253, 1992 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 17 Konu: 4
  • Basım Tarihi: 1992
  • Dergi Adı: PLASTICS RUBBER AND COMPOSITES PROCESSING AND APPLICATIONS
  • Sayfa Sayısı: ss.247-253

Özet

Ductile pipe grade polyethylenes can, under severe conditions, fail by Rapid Crack Propagation (RCP). Critical pressures (below which RCP always arrests) of medium density and modified high density polyethylene pipes, measured using a small-scale pressure test, identify temperature and thickness mediated brittle-ductile transitions which effectively characterise their performance in full-scale tests. Instrumented Charpy tests on specimens thinner than the pipe wall reflect the transition temperatures only qualitatively. High Speed Double Torsion tests across a spectrum of crack velocities yield plane-strain dynamic crack resistance data, even at 0-degrees-C and for specimens only 6-mm thick; they therefore conceal the ductile-brittle transition, but more effectively characterise the worst case of a highly constrained crack in thicker pipe.