Finite element estimation of carcass wet collapse capacity in unbonded flexible pipe
Date of Issue2016
School of Mechanical and Aerospace Engineering
The collapse capacity of carcass layers under wet collapse condition for an unbonded flexible pipe has been investigated in this thesis. Numerical simulations using commercial finite element software package ABAQUS v6.13-2 have been performed for establishing the same. An alternative finite element setup scheme titled uCavity model” is proposed. Its benefits over the standard modelling schemes mentioned in literature has been reviewed and commented. Analytical calculations based on the formulations proposed by Gay Neto and Arruda Martins have been used for validation. Effect of initial API ovalization and its orientation on the collapse capacity has been studied on all models. Sensitivity studies recorded the effect of local imperfection on the collapse capacity and shape of collapse. All schemes were seen to predict a reduction of collapse strength with increasing ovalization. However, one of the benefits of cavity model seen from this study is its ability to predict a clear critical collapse point and a suggestive post-collapse behaviour using the ABAQUS/Standard solver itself.