Effective Limit Stresses Estimation of Lattice Structures for Biomedical Applications : A Sensitivity Analysis

Abstract

Recent advancements in additive manufacturing have enabled the design of tailored lattice structures, suitable for a range of applications, including biomedical implants. The design of lattice structures for biomedical applications requires accurate prediction of both stiffness and strength. This study presents a numerical framework to estimate the effective elastic properties and limit stresses of periodic lattice structures using a strain energy-based homogenization method combined with an efficient method to assess limit stresses along the different directions of the lattice structures. Four cell topologies (ACC, BCC, SC-BCC, F2CC) with varying strut diameters were analysed. The effective elastic constants were computed by applying periodic boundary conditions to the representative volume element of the lattice structure. To estimate the effective limit stresses, a method based on the volume-averaged stress over a subset of the most stressed elements (Ω) was proposed. Three selection strategies for Ω were developed and evaluated through sensitivity analyses. Results show that the estimated limit stresses strongly depends on the definition of Ω. The proposed method enables early-stage design of lattice-based implants with tailored mechanical behaviour and controlled failure limits, enhancing safety and biological integration, contributing to the development of computational tools for patient-specific implant design.