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

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. • Tensile tests on Polyamide 12 bulk specimens to obtain the constitutive behaviour. • Tensile tests on lattice specimens with different geometry. • Periodic boundary conditions to perform homogenization of lattice units. • Hill yielding criterion to model the anisotropic plastic behaviour of lattice units. • Simplified method to model the anisotropic plastic behaviour of lattice units.