Mechanical Behaviour of Lined Pipe

Abstract

Installing lined pipe by means of the reeling installation method seems to be an attractive combination, because it provides the opportunity of eliminating the demanding welds from the critical time offshore and instead preparing them onshore. However, reeling of lined pipe is not yet proven technology. From previous research it is known that lined pipe undergoing high plastic strains during reeling, exhibits liner wrinkling and extensive ovalisation. The main objective of this study is to investigate the possibility of installing lined pipe by means of the reeling installation method. A combination of pure bending numerical models and full scale four point bend tests were used to reach the objective. The cascade of events exhibited by the lined pipe in pure bending was fully understood. Liner wrinkling appeared to be the main failure mode of lined pipe during bending. The sensitivity of the wrinkling behaviour of the confined liner in pure bending for several geometric, material and contact parameters was examined by means of a parameter study. From this study it is concluded that reeling of lined pipe can become technically feasible, most effectively by adjusting the geometric and contact parameters of the lined pipe.