Comparison of Soil Modeling Strategies with Springs in Free-Span Submarine Pipelines

Resumo

The fatigue life of submarine pipelines is significantly influenced by structural parameters and environmental conditions to which they are exposed. Numerous studies have focused on modeling this issue using the Finite Element Method to determine frequencies and natural modes of vibration. The models consist of pipeline sections, with some segments in free spans and others supported by soils that can be represented by contact surfaces or sets of springs constituting an elastic foundation. This work aims to evaluate different strategies for representing soil stiffness using springs in a finite element model. Additionally, we investigate the incorporation of the solution for a semi-infinite beam on an elastic foundation to calculate the stiffness of the modeled endpoints. We analyze different element lengths in a free-spanning pipeline model to quantify the influence of various approaches on frequencies and natural modes of vibration. Therefore, this work emphasizes the relevance of parametric studies in modeling submarine pipelines, with particular emphasis on accounting for soil stiffness.