Design, additive manufacturing, and characterisation of a three-dimensional cross-based fractal structure for shock absorption. (December 2022)

• Record Type: Journal Article
• Authors: Viccica, Marco; Galati, Manuela; Calignano, Flaviana; Iuliano, Luca
• Is Part Of: Thin-walled structures. Volume 181(2022)
• Publication Date: 2022-12
• Subjects: 3D Greek cross fractal -- Personal protective equipment -- Selective laser sintering -- 3D printing -- PA12; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2022.110106
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: Fractal geometries have the potential to enhance the mechanical performances of materials. However, these geometries are often unfeasible using traditional processes. Focusing on selective laser sintering (SLS), an additive manufacturing process, this study investigates the mechanical properties of a 3D Greek Cross fractal. The mechanical behaviour of the structure is numerically investigated under quasi-static and dynamic compressive loads in the case of shock-absorbing head protection equipment applications. The material model is tailored and validated by experimental results. The energy absorption results higher up to 77% than traditional foam. However, for features smaller than 1 mm, the induced process defects drastically reduce the mechanical performance of the structure. Highlights: Additive manufacturing is effective answer to produce 3D complex fractal structures. 3D cross based fractal structure (3D-CFS) is investigated for impact absorption. A 3D FE model predicts the mechanical and bending behaviour of the 3D-CFS. Experimental analyses on the PA12 samples produced via SLS validate the FE model. The 3D-CFS structure absorbed up 77% more energy than a traditional EPS foam.