Compression testing of additively manufactured continuous carbon fiber-reinforced sandwich structures

The novel, additive manufacturing technique, continuous lattice fabrication, combines the advantages of continuous fiber-reinforcement with those of additive manufacturing. This enables the generation of fiber-reinforcement within a single layer and especially along an out-of-plane load path inside all spatial dimensions. This study is a test-related evaluation of sandwich panels with lattice core structures modifying a compression test. The specimens were manufactured differentially via plug and bond and automatically using continuous lattice fabrication. Additionally, the spatial arrangement of the rods within the lattice core structure varied in terms of base area. The ultra-lightweight sandwich panels have lattice core structures with core densities < 10 mg × cm−3. The material testing was performed by a modified compression test at room temperature. The damage analysis of the single rods shows current deficits and future potentials for optimization of lattice core structures. It could be shown that sandwich panels exhibit a compression strength of up to 0.30 MPa at a core density of 6.57 mg × cm−3. Using a dimensionless lightweight index demonstrates a mechanical performance on a level comparable with that of selected core materials.