Efficient fracture assessment of pipelines. A constraint-corrected SENT specimen approach

Reeling has proven to be an efficient and cost effective method for offshore pipelaying. During the reeling process the pipe undergoes deformation that can strain the material by 1–2%. The existing failure assessment methods often turn out to be too conservative to allow such a strain level in the structure. The amount of conservatism can be significantly reduced by using a new failure assessment approach developed by SINTEF. This approach depends on finite element calculations for establishing the non-linear fracture mechanics parameters and the stress and strain distributions in the pipe. The present study addresses the performance of shell and line spring finite elements as a cost effective tool for performing such numerical calculations.