This paper provides detailed insights into the external pressure vessels. External pressure vessels are designed to perform under extreme operating conditions, so the selection of material and geometry along with stress analysis are fundamental for their optimal efficiency. The objective of this research is to provide a case study of the material, design, and stress generated in the pressure vessel to make it suitable for thermal and load-bearing applications in the aerospace industry. An aluminum alloy was chosen as the design material due to its low density and high strength. The modeling geometry of the alloy was constructed using the ASME section-VIII division-I div code. After the performed Finite Element Analysis (FEA), modeling was carried out deploying the ANSYS design modeler to obtain the stress concentration and failure mode of the model. The present study demonstrates the behavior of a structure under applied load and identifies the weak areas of its geometry. Based on the external stress at the center of the structure, the maximum and minimum stresses computed are 0.763 MPa and 0.00803 MPa, respectively. It was also found that the maximum strain is generated at the center of the structure and is equal to 1.0834e-6 mm/mm, the maximum deformation is equal to 0.00109 mm and also occurred at the center, while the shells of the model are unable to undergo any deformation. FEA results agree with the analytical results, as the errors for hoop stress and equivalent strain are 4.8% and 1.8%, respectively. Thus, the proposed method can be applied to predict the equivalent stress, equivalent strain, total deformation, and stress intensity, which are required for the structural integrity analysis of pressure vessels.

The interactions between subsea pipelines and the seabed generate complex vibratory responses that can compromise structural integrity, yet these interactions remain difficult to characterize with sufficient fidelity for design purposes. This study examines a numerical workflow for incorporating hydrodynamic forces and displacement-dependent pipe-soil interaction into the finite element analysis of a nominally 400 m subsea pipeline. The hydrodynamic formulation includes irregular wave kinematics, directional spreading, current effects, and force corrections related to pipeline movement, while the geotechnical representation uses prescribed pipe-soil contact and lateral resistance relationships. The workflow links local resistance characterization with the global structural response and investigates the sensitivity of calculated lateral displacement to applied stabilization weight and seabed strength assumptions. This approach enables computationally efficient structural analysis without sacrificing the fidelity needed to assess whole-system performance, directly addressing the central modeling challenge posed by the pipe-soil interface. Over a 100-year simulated service life, the maximum lateral displacement recorded across the 400 m pipeline reached 5.43 m, while displacement peaked at approximately 3.98 m under a chain weight of 18.37 kg. These results demonstrate the model’s sensitivity to key design parameters governing pipeline stability. The analysis provides an implementation-based case study for assessing the consequences of alternative seabed-resistance assumptions rather than establishing a new soil constitutive model or an independently validated through-life design procedure, and it provides a robust foundation for future subsea pipeline engineering practices.