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Creep analysis of polymeric pipes under internal pressure
Author(s) -
Guan Z. W.,
Boot J. C.
Publication year - 2001
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10795
Subject(s) - creep , materials science , internal pressure , polyethylene , composite material , hyperelastic material , ultimate tensile strength , viscoplasticity , constitutive equation , high density polyethylene , viscoelasticity , modulus , service life , structural engineering , finite element method , engineering
Medium density polyethylene pipes have been used in the water and gas industries for over a decade. One of the major problems with these pipes is creep under their service pressures. Life prediction is usually based on the secondary creep path until the onset of tertiary creep. Constitutive models such as visco‐hyperelasticity and elasto‐viscoplasticity can be used to make such prediction. Owing to complexity, the latter is usually used in numerical modeling, Medium density polyethylene is an extremely ductile material with a low modulus of elasticity. The corresponding elongation prior to rupture under a tensile creep test can reach a few hundred percent. The appropriate creep law must be established before any life prediction can be made. In this paper, based on a creep law obtained from a series of material creep tests under different stress levels, a visco‐hyperelastic model was developed to simulate Medium density polyethylene pipes under internal creep pressures. Reasonably good correlation has been obtained between the experimental results and the theoretical analysis.