Designing and manufacturing replacement cancellous bone structures by lattice structures and Additive Manufacturing (AM) techniques is an effective method to create lightweight orthopedic implants while ensuring that they are mechanically compatible and their osseointegration ability with the host bone. In this article, we suggest a new design based on three lattice structures from triply periodic minimal surfaces (TPMS) with a different volume porosity to replace cancellous bone based on predicting the mechanical stiffness. To predict the mechanical stiffness, the relationship between the effective modulus of elasticity and different porosity ratios of the lattice structures was determined by using three methods: i) finite element modeling (FEM) simulation, ii) Gibson and Ashby method and iii) a uniaxial compression test after manufacturing the lattice structures by using Fused Filament Fabrication (FFF) Technology. To demonstrate the efficiency of our approach, the comparison of both numerical and experimental results showed that the effect of structure difference and porosity ratio of lattice structures on the mechanical stiffness values effectively match the cancellous bone in terms of elastic modulus and porosity ratio.

Designing and manufacturing lattice structures with Topology Optimization (TO) and Additive Manufacturing (AM) techniques is a novel method to create light-weight components with promising potential and high design flexibility. This paper proposes a new design of lightweight-graded lattice structures to replace the internal solid volume of the turbine blade to increase its endurance of high thermal stresses effects. The microstructure design of unit cells in a 3D framework is conducted by using the lattice structure topology optimization (LSTO) technique. The role of the LSTO is to find an optimal density distribution of lattice structures in the design space under specific stress constraints and fill the inner solid part of the blade with graded lattice structures. The derived implicit surfaces modelling is used from a triply periodic minimal surfaces (TPMS) to optimize the mechanical performances of lattice structures. Numerical results show the validity of the proposed method. The effectiveness and robustness of the constructed models are analysed by using finite element analysis. The simulation results show that the graded lattice structures in the improved designs have better efficiency in terms of lightweight (33.41–40.32%), stress (25.52–48.55%) and deformation (7.35–19.58%) compared to the initial design.