Lang, Pinter, Stern
Lifetime Analysis # 2001 Munich
Engineering polymers, in particular special grades of poly(ethylene) (PE), are gaining importance in many pipe applications with targeted service lives of several decades. To ensure proper performance of such pipes over the required lifetime, polymer physics and mechanics concepts are needed which adequately account for effects associated with the presence of defects in real pipes and the effects of time, temperature, environment and local loading conditions. This article is concerned with the applicability of linear elastic fracture mechanics (LEFM) to predict the time-to-failure of pressurized PE pipes in the quasi-brittle failure regime. As to the micro-mechanisms of failure, particular attention is given to the occurrence of general pipe aging and local crack tip aging, and to effects of stabilization on creep crack growth kinetics and pipe failure times.
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