INVESTIGADORES
OTEGUI Luis Jose
artículos
Título:
Numerical tool to model collapse of polymeric liners in pipelines
Autor/es:
F. RUEDA; J,L. OTEGUI; P.M. FRONTINI
Revista:
ENGINEERING FAILURE ANALYSIS
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Año: 2012 vol. 20 p. 25 - 34
ISSN:
1350-6307
Resumen:
Polymeric liners are widely used in the gas and oil transportation industry. They provide
improved corrosion resistance to metallic tubes and they also are used in rehabilitation
of deteriorated pipelines. Oil derived gases permeate across the liner wall; which during
rapid depressurization produce external pressure that in many cases lead to buckling collapse
of the liner. A number of simple models to calculate critical pressure for buckling collapse
are available, but these models do not account for surface or geometrical defects that
are usually present in liners under service conditions. The non-linear characteristics of the
problem generate convergence issues that make it difficult for classical FEM to reproduce
the actual behavior of experimental curves. This paper is concerned with simulation of the
buckling collapse of HDPE liners. Three ways to raise and resolve the issue of liner collapse
have been used in this study. Two of them, the General Static Model and the Riks Static
Method have been used before for similar simulations. Innovatively in this work, a nonconventional approach to finite element analysis (FEA) which makes use of hydrostatic
elements has been tried for the first time. This approach has the inherent advantage of
allowing the use of time-dependent material constitutive models. Three types of constitutive
models were considered to model HDPE stressstrain behavior: elastic, ideal elastic
plastic and an elastic-strain hardening plastic model that takes into account the complete
deformation curve determined from uniaxial tensile experiments. Validation of the simulations are made by comparing the results with analytical, or semi-analytical models and
with results from previous publications. The collapse of polymeric liners in the presence
of external pressure is adequately reproduced by the finite elements method (FEM) models
developed.