In this paper a numerical model is proposed for Mechanically Lined pipe (MLP). LASER based scanning techniques were used to capture local straining of the liner and Digital Imaging Correlation (DIC) of the backing steel outer during simulated reeling trials. This included wrinkling generated by an unexpected anomaly near the transition area of one test string. Data was collected pre-reeling, during reeling and post-reeling. The numerical model developed to simulate the bending trial corresponds well with test data, proving the method useful for further MLP modelling studies.
Mechanically lined pipe (MLP) is a cost-effective solution to transmit corrosive hydrocarbon fluids. A carbon steel host pipe shelters a thin tubing layer made of Corrosion Resistant Alloy (CRA). The thin tubing is inserted and expanded to fit the inner surface of the host pipe. A specific failure mode can occur based on delamination and collapse of the liner, known as "wrinkling", when installed by reel-laying (Vasilikis and Karamanos, 2012), or under repeated large bending (Bartolini et al., 2017). Several works were performed to address specifically the conditions that may trigger a wrinkle, from a numerical perspective (previous references), or combining experimental and numerical studies (Toguyeni and Banse, 2012). Some proposed criteria to anticipate the situation where liner wrinkling may occur e.g.: JIP for lined and clad pipelines (2018), Tkaczyk et al. (2020), Le et al; (2021). Test campaigns were reported in recent years with dedicated instrumentation based on laser scanning to quantify the liner response and calibrate finite element model, e.g. Focke et al., (2007). High resolution measurements generate a large amount of data that requires a specific processing in order to get valuable interpretation such as the one described by Harrison et al. (2016). Some test programmes focused on local feature that could initiate a wrinkle such as a weld (Jones et al., 2021) or a liner imperfection (Pepin et al., 2019). However, to the authors knowledge, there is no MLP bending test involving an anomaly that specifically triggers a wrinkle that is measured with high resolution instrumentation and simulated through Finite Element Analysis. This paper proposes a comparison between experimental and numerical experience for such a case.
