Optimal design and additive manufacturing of novel reinforcing elements for composite materials

We experimentally investigate on the use of additive manufacturing technologies for the design and fabrication of innovative reinforcing elements of novel composite materials. We perform short-beam shear tests on cement mortar specimens reinforced with additively manufactured reinforcing fibers made of photopolymers or a titanium alloy. The fracture toughness, shear capacity and first crack strength of the examined materials are estimated based on the provisions of different international standards for construction materials. We also characterize the surface morphology of the examined fibers through microscopy analyses before and after testing. The given results highlight that the microscopic or macroscopic nature of the surface roughness of the analyzed fibers greatly influences the energy absorption capacity of the final materials, while the nature of the fibers' material (metallic/polymeric) is of central importance in terms of strength properties. The present study represents a first step in the direction of designing reinforcing elements with hierarchical structure to form fabrics, fibers and coatings of groundbreaking reinforcements for next generation composites, profiting from the rapid prototyping capabilities of additive manufacturing technologies at different scales.