Design and Manufacturing of a Composite Lattice Structure Reinforced by Continuous Carbon Fibers

New techniques have been developed to make materials with a periodic three-dimensional lattice structure. The high stiffness per unit weight and multifunction of such lattice structures make them attractive for use in aeronautic and astronautic structures. In this paper, epoxy-soaked continuous carbon fibres were first introduced to make lattice composite structures, which maximize the specific load carrying capacity. A micromechanical analysis of several designs, each corresponding to a different manufacturing route, was carried out, in order to find the optimized lattice structure with maximum specific stiffness. An intertwining method was chosen and developed as the best route to make lattice composite materials reinforced by carbon fibers. A sandwich-weaved sample with a three-dimensional intertwined lattice structure core was found to be best. The manufacturing of such a composite lattice material was outlined, In addition to a high shear strength of the core and the integral manufacturing method, the lattice sandwich structure is expected to possess better mechanical capability.

Design and performance evaluation of additively manufactured composite lattice structures of commercially pure Ti(CP-Ti)

Ti alloys with lattice structures are garnering more and more attention in the field of bone repair or regeneration due to their superior structural,mechanical,and biological properties.In this study,six types of composite lattice structures with different strut radius that consist of simple cubic(structure A),body-centered cubic(structure B),and edge-centered cubic(structure C)unit cells are designed.The designed structures are firstly simulated and analysed by the finite element(FE)method.Commercially pure Ti(CP-Ti)lattice structures with optimized unit cells and strut radius are then fabricated by selective laser melting(SLM),and the dimensions,microtopography,and mechanical properties are characterised.The results show that among the six types of composite lattice structures,combined BA,CA,and CB structures exhibit smaller maximum von-Mises stress,indicating that these structures have higher strength.Based on the fitting curves of stress/specific surface area versus strut radius,the optimized strut radius of BA,CA,and CB structures is 0.28,0.23,and 0.30 mm respectively.Their corresponding compressive yield strength and compressive modulus are 42.28,30.11,and 176.96 MPa,and 4.13,2.16,and 7.84 GPa,respectively.The CP-Ti with CB unit structure presents a similar strength and compressive modulus to the cortical bone,which makes it a potential candidate for subchondral bone restorations.