Additively Manufactured Foot Insoles Using Body-Centered Cubic (BCC) and Triply Periodic Minimal Surface (TPMS) Cellular Structures

Abstract

This study presents the development of insoles using 3D scanning and additive manufacturing; additionally, the feasibility of implementing cellular structures in their design was evaluated. Using finite element models, the displacements and Von Mises stresses in the insoles were obtained considering the exerted pressures of a person during walking. The insoles developed in this work presented a decrease of 91.48% in deformation while the maximum Von Mises stress increased by 32.62%, compared with what other authors reported. The Von Mises stresses and displacements in the insole were calculated when two cellular topologies, triply periodic minimal surfaces (TPMS) and body-centered cubic (BCC), and different relative densities (10.33%, 14.67%, and 20.19%) were implemented. When compared to solid insoles, the Von Mises stresses and displacements for the models with cellular structures increased. The maximum Von Mises stresses and displacements resulted for the insoles with a relative density of 10.33%; for the insole with the BCC cellular structure, the displacement was 2.06 mm, and the Von Mises stress was 22.17 MPa, while for the TPMS structure, these were 2.7 mm and 23.84 MPa, respectively. The designs were additively manufactured, and the printing defects were visually characterized.

Keywords

• 3D scanning
• additive manufacturing
• cellular structures
• finite element method
• insole