Modelling the Anisotropic Elasto-Plastic Response of 3D-Printed Polymer Parts

This work develops and validates finite element models to simulate the anisotropic elasto-plastic behaviour of 3D-printed polymers. Specifically, 3D printed thermo-responsive Shape-Memory Polymer (SMP) coupons tested at room temperature are analysed. The modelling strategy employs built-in constitutive formulations within ABAQUS®, including Hill’s anisotropic plasticity and the Tsai-Hill failure criterion, thereby avoiding the need for user-defined material subroutines. The elastic response is represented through an orthotropic approximation, while plastic hardening is calibrated from reference experimental data. The resulting 3D FE models are able to capture the influence of raster angle on tensile performance, accurately predicting the variations in modulus, strength, and failure strain observed between aligned and off-axis printing orientations. Numerical-experimental correlation demonstrates that the proposed approach reproduces both the stress–strain response and the orientation-dependent failure patterns with satisfactory accuracy. These results confirm the suitability of efficient, commercially available constitutive models for representing the mechanical response of additively manufactured polymers, such as SMPs. The methodology provides a reliable framework for the design and optimisation of anisotropic 3D-printed structures, with potential applications in biomedical, aerospace, and automotive engineering.