Unveiling the mechanics of micro-LPBF manufactured hierarchical composites : a novel FE2-nested homogenisation approach

Abstract

Multi-level periodicity is a ubiquitous structural feature of natural composites. Conventional homogenisation techniques can effectively address the mechanism of uniform periodic structures, while encountering challenges in efficiently characterising the performance of multi-scale hierarchical structures. This study presents an FE2 (Finite Element Square)-nested homogenisation elastic-calculating method, integrating RVE-based homogenisation 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 homogenisation 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 customisation and enhancement of complex multi-level design.