Automated FE Analysis of a Stiffened Tank Pressure Vessel using Shell-Solid Multi-Fidelity Modeling

Stiffened thin-walled pressure vessels are widely used, especially in the aerospace, marine, automobile, and chemical industries. Accurate structural analysis of such complex structures under external and internal pressure loads is key to making critical design decisions during the conceptual and preliminary stages. With the advancements in adaptive optimization frameworks, multi-fidelity finite element (FE) models (shell-solid coupled) are increasingly sought in the early stages of design development for accurate and efficient analysis. However, the time and effort required to create such mixed finite element models with acceptable meshes for highly complex structures is still significant and is a major bottleneck in the FE modelling. Thus, automation of FE model creation and mesh generation is critical for advancements in technology. A major hurdle in automating highly complex structural FE models is the generation of robust meshing. This paper presents a framework for the automation of multi-fidelity model development from the solid and shell models using parameterization and scripting within the commercial FE packages. Additionally, issues related to the automated meshing of highly complex assemblies is discussed, and a volume decomposition scheme is proposed based on face partitions. A comparison of the all-solid, all-shell and different solid/shell multi-fidelity models of a highly complex stiffened thin-walled pressure vessel under external pressure and internal tank pressure is presented. Results reveal that automated generation of mixed models in an integrated manner including the geometry creation, meshing, and post-processing is capable of significant computational savings and reducing considerable interactive effort involved in analyzing complex structures.