Unveiling the Mechanics of Micro-LPBF Manufactured Hierarchical Composites: A novel FE2-nested Homogenization approach

Multi-level periodicity is a ubiquitous structural feature of natural composites. Conventional homogenization techniques can effectively address the mechanism of uniform periodic structures, while encountering challenges in efficiently characterizing the performance of multi-scale hierarchical structures. This study presents an FE2 (Finite Element Square)-nested homogenization elastic-calculating method, integrating RVE-based homogenization for primary periodicity and nested Direct FE2 for secondary periodicity. Harnessing micro-LPBF process, specimens with multi-level periodicity are fabricated. The high-precision manufacturing is integral for unlocking the design potential of macro-micro hierarchical material, allowing for the creation of components with intricate multi-scale features. Mechanical testing of specimens validates the accuracy of FE2-nested homogenization method, demonstrating its effectiveness in predicting the elastic responses of multi-level periodic structures. Furthermore, the FE2-nested method is employed to elucidate the macro-micro interaction mechanisms. It underscores potential to drive innovations in hierarchical composite material, providing a method basis for mechanical customization and enhancement of complex multi-level design.