114 - TOWARDS STANDARDIZATION IN COMPOSITE PRESSURE VESSEL TESTING: A BUILDING-BLOCK APPROACH FOR ACCURATE MATERIAL CHARACTERIZATION (CompTest 2025)

Gabriel Eduardo Rojas Valenzuela, Miranda Cruz Policroniades, Shuyu Song, Xianshuo Lyu, Dennis Bublitz, Leo Körber, Klaus Drechsler

In the application of Composite Overwrapped Pressure Vessels (COPVs), filament winding is one of the most widely used and cost-effective manufacturing techniques. Despite its extensive use over several decades, standardized methods for characterizing wound components, particularly for pressure vessel applications, remain limited. Current standard procedures for determining mechanical properties involve manufacturing samples from flat plate, which are then used for the material card. However, these flat specimens fail to represent key parameters of the actual manufacturing process for pressure vessels, such as compaction caused by the fiber tension [1]. Characterizing flat samples is easier, as the loads and force introduction are well-defined, but these tests fail to represent real manufacturing properties. Curved sample tests, such as the split disk, provide insights into material properties by incorporating real manufacturing parameters but often fail to capture actual failure mechanisms accurately, and defining load introduction is more complex. This highlights the need for an intermediate test for curved samples that balances representative process influence with straightforward load introduction and execution. To better understand material behavior, we propose adapting the building block approach from the testing pyramid [2] for pressure vessel applications, combining tests for flat and curved samples at different pyramid levels, with both physical and virtual testing. This research focuses on developing a simplified and effective methodology for characterizing wound samples to optimize the manufacturing process. At the element level, the 3-point bending test of curved beams is proposed as an intermediate step between the split disk and flat specimen tests.

Date
21.05.2025.
Keywords
ressure Vessel, Filament Winding, Finite Element, Digital Image Correlation, Curved Beam Theory