A Numerical Study on Prediction of Collapse Pressure of UOE Pipes

UOE pipe is widely used for thick-walled offshore pipes thanks to its productivity. UOE pipe is obtained through successive plastic forming stages which exert changes in the material strain- stress behaviour due to hardening and Bauschinger effects. Ovality and residual stress of complex aspect are also induced by the repetition of plastic forming and elastic spring back. These factors make it difficult to predict the collapse pressure of the pipe at the design stage. However the accurate prediction of the collapse pressure is essential for cost and time efficiency considering that sometimes the total length of the pipeline runs over several thousands of kilometers. In this study, finite element analysis is conducted to track the material properties all along the forming process and the collapse pressure is assessed using data mapping technique. Finally, the influence of the extent of pipe expansion on collapse pressure of the UOE pipe is examined.