Structural Analysis of Non-prismatic Column Using Finite Element Approach

Offshore pipelines are subjected to various types of loading, depending upon the sub-sea conditions during their design life. Buckling is a major structural instability problem in the offshore pipelines operating at high pressure and high temperature, along with other causes. Various kinds of non-prismatic sections are generally used in special areas of the pipeline system. The present research work focuses on estimating the structural response (bucking strength, in particular) of the non-prismatic offshore pipelines. Eigenvalue buckling analysis using the Finite Element (FE) method was conducted to find the buckling strength and mode shape of the pipeline model. The non-prismatic pipeline was modeled as 1-D and 3-D FE models; the 1-D model was analyzed using the MATLAB program, and the complete 3-D model was analyzed using the ANSYS workbench. Both the 1-D and 3-D numerical analysis results were compared and verified experimentally. The results of the analysis and their convergence pattern were also discussed.