Mechanical Behavior of the Risers With Helicoidally Weld Under Combined Actions

Abstract

The growing need to satisfy the national oil industry demand has required the evaluation and retrofit of the existing pipelines, in addition to create new risers for transportation and distribution of oil products. The current development of offshore structures requires better designs of the risers capable to assuring an optimal level of security. It is common to get situations, in the performance of fixed offshore platforms, in which risers might be found with lowly internal pressure or empty due to maintenance or repairing. This condition could represent an unfavorable situation that might become highly critical given the conditions they are found in. Therefore, this research is focused to study the mechanical behavior and their structural integrity of the pipelines such as, risers with helicoidally welds under combined load (external pressure, bending moment and axial compression). In particular, for safety prediction, the failure modes and uncertainties involved in each loading condition need to be incorporated in the analysis in order to specify the pipelines use thresholds that keep them over acceptable safety levels within their operating lifetimes.