The demands for a high-performance prosthesis include high strength and low weight. This study addresses the optimization of a new tube concept, made of composite material, which makes use of an isogrid and internal layer. For the methodological procedure, a response surface methodology (RSM) was used to define in what quantity, under what conditions and which data should be collected during a given experiment, seeking to satisfy the highest statistical precision and the lowest cost in the response. After RSM analysis, the finite element method was used for structural calculations for each condition of the experiment. The numerical results allowed the creation of a meta-model capable of translating the global structural behaviour. Thus, it was possible to optimize the parameters that were translated as responses applied to a lattice structure by particle swarm optimization and the Lichtenberg algorithm (LA). Comparison of the results demonstrated the good performance of the LA.

Nowadays, the additive manufacturing of multifunctional materials is booming. The fused deposition modeling (FDM) process is widely used thanks to the ease with which multimaterial parts can be printed. The main limitation of this process is the mechanical properties of the parts obtained. New continuous-fiber FDM printers significantly improve mechanical properties. Another limitation is the repeatability of the process. This paper proposes to explore the feasibility of printing parts in continuous carbon fiber and using this fiber as an indicator thanks to the electrical properties of the carbon fiber. The placement of the fiber in the part is based on the paths of a strain gauge. The results show that the resistivity evolves linearly during the elastic period. The gauge factor (GF) increases when the number of passes in the manufacturing plane is low, but repeatability is impacted. However, no correlation is possible during the plastic deformation of the sample. For an equivalent length of carbon fiber, it is preferable to have a strategy of superimposing layers of carbon fiber rather than a single-plane strategy. The mechanical properties remain equivalent but the variation in the electrical signal is greater when the layers are superimposed.