Lightweight design of polymeric thin-walled components: Latticization and elastic–plastic homogenization

Abstract

The demand for lightweight yet mechanically robust components has driven the exploration of lattice structures, which offer superior weight-to-strength ratios compared to traditional bulk materials. This study investigates the elastic–plastic behaviour of Polyamide 12 (PA12) lattice structures manufactured via multi jet fusion (MJF). The research combines experimental, numerical, and theoretical approaches to develop a robust framework for the mechanical homogenization of these structures. Tensile tests were performed on bulk and graded lattice specimens to characterize their constitutive behaviour. A simplified homogenization method, integrating periodic boundary conditions (PBCs) with the Hill yielding criterion and Levy-Mises plastic flow rule, was developed to model the anisotropic plastic response of representative volume elements (RVEs). This framework accounts for direction-dependent hardening, enabling efficient prediction of lattice behaviour under complex loading scenarios. Numerical simulations of homogenized RVEs reflected experimental results with a good level of accuracy, validating the model’s ability to capture both elastic and plastic deformation regimes. Findings highlight the potential of the proposed methodology for structural optimization and mechanical performance prediction in applications requiring lightweight and durable materials, such as automotive, aerospace, and biomedical devices.

Keywords

• Polyamide 12
• Multi jet fusion
• Lattice structures
• Homogenization
• Periodic boundary conditions
• Anisotropic plastic behaviour