Modeling of 3D printed reinforced composites with complex microstructures

Abstract

Bouligand structures, characterized by stacked fibers with varying pitch angles between adjacent layers, have garnered significant interest for their ability to enhance toughness under bending or impact loading. However, their mechanical behavior under compressive loading has not been explored, particularly the interplay between pitch angle, relative density, and compression properties in 3D printed Bouligand lattice structures, which remains inadequately understood. This paper aims to examine the mechanical response of 3D printed Bouligand structures under compressive load, employing finite element modeling and being complemented by experimental results for validation. Additionally, the study focuses on how pitch angle and relative density influence the mechanical properties and damage modes of different Bouligand structures. It has been observed that a relative density of 1 in the Bouligand structure significantly enhances the material's transverse compression properties by inducing more uniform deformation in other directions. As the relative density diminishes, a larger pitch angle mitigates the decline in mechanical properties, with a 90-degree pitch angle maintaining optimal properties at lower relative densities. Variations in pitch angle and relative density affect the stress distribution within the Bouligand structure, particularly influencing the magnitude of the shear stress S23. The unique characteristics of Bouligand structures present promising avenues for developing new lightweight, high-strength structural materials, particularly for applications in the automotive and aerospace industries.