Abstract
This study presents a multiscale modeling approach for the design and analysis of a Type IV composite pressure vessel subjected to an internal pressure of 70 MPa. The vessel's composite section comprises carbon fiber and epoxy resin. Micromechanical properties were determined using two methods: the Material Designer module in Ansys Workbench and a periodic boundary condition (PBC) approach implemented in Mechanical APDL. Three fiber geometries-actual scanned, circular, and elliptical-were considered to assess their influence on the homogenized material properties. A macroscale finite element model was developed incorporating variable layer thicknesses in the dome regions and varying winding angles, constructed using an algorithm within the Ansys ACP module. Failure analyses employed the Puck and Hashin criteria for constituent-level assessment and the Tsai-Wu criterion for the homogenized composite. Dehomogenization techniques were applied to extract strain tensors from critical regions, which were then imposed on representative volume elements (RVEs) reflecting the different fiber geometries. Comparative analysis of the RVEs provided insights into the initiation and progression of damage within the composite structure. The dehomogenisation method used in this study makes it possible to investigate the state of stress on a micro scale. In addition, the results obtained were compared with the strength criteria of the composites.