Finite element modelling of 3D printed continuous carbon fiber composites: Embedded elements technique and experimental validation

A finite element approach for the simulation of composite parts with complex geometry realized by continuous fiber reinforced additive manufacturing is described. The embedded elements technique was adopted to accurately represent the layout of matrix and fibers while retaining an effortless finite element model setup. A simple specimen geometry with three different fiber layouts was chosen for experimental testing to allow the comparison of the embedded elements approach with conventional analytical or numerical methods for stiffness assessment. A complex specimen geometry with multiple notches was also printed, with three different fiber layouts, to further validate the use of the embedded elements technique in presence of 3D printed fiber deposition patterns for which conventional methods could not be applied. This study showed that the embedded elements approach, compared to more traditional techniques based on homogenization, may allow an accurate prediction of stiffness with the additional ability to model complex fiber deposition patterns, a simpler finite element analysis setup and a potentially richer output.