A numerical study on the predicted fiber orientation of large area extrusion deposition additive manufactured composites

Abstract The recent‐emerging Large Area extrusion deposition Additive Manufacturing (LAAM) provides a low‐cost and high‐efficient alternative manufacturing approach for industries like automotive and aerospace. Fiber orientation information significantly determines the material performances of LAAM‐produced short fiber reinforced composites. Numerical studies have been performed to better understand the microstructural formation of the fiber orientation in deposited beads. The fully coupled flow/orientation analysis approach has been applied for LAAM deposition flow modeling. In contrast, the orientation analysis is still limited to the classic Folgar‐Tucker Isotropic Rotary Diffusion (IRD) model. This paper employs the advanced principle Anisotropic Rotary Diffusion Reduced Strain Closure (pARD‐RSC) orientation evaluation model to estimate the fiber alignment of the LAAM flows, which is firstly used in the simulations of extrusion deposition flows with free surface boundaries. The effects of constant parameters of the pARD‐RSC model are investigated. It is found that predicted fiber orientation results in the flow end are primarily sensitive to the value of the strain slip factor. The initial fiber orientation condition of the flow inlet is also studied. By comparing the computed results with experimentally reported data, it is found that the initial fiber orientation state of the flow inlet significantly impacts the fiber alignment patterns in the deposited beads.