Finite Element Modelling of Additive-Manufactured PA11

The ability to manufacture geometrically complex structures with superior mechanical properties is a key value proposition for the use of additive manufacturing techniques. However, this advantage can only be fully realised when the part design is driven by the knowledge of the mechanical behaviour of the selected material. Finite element modelling can act as a convenient tool for applying said knowledge during the design process. However, anisotropy in mechanical properties of additive-manufactured parts and the non-linear elasticity of polymeric materials have made it challenging to model additive-manufactured polymers without the use of complex and custom material models. In this work, polyamide-11 (PA11) fabricated with the Multi Jet Fusion (MJFTM) process was modelled using elastic-plastic material models native to a commercial finite element package – Abaqus. The Nelder- Mead method was applied to calibrate the material model with experimental tensile and compression test data. Simulated flexural properties were then compared against the experimental bending test data to verify the material models. It was found that the elastic-plastic model, applied with the combined hardening option, accurately predicts material flexural modulus.