A multiscale approach to understand the effects of design parameters on the elastic behavior of 3D orthogonally woven composites

Abstract

This study aims to investigate the effect of various parameters on the elastic constants of three-dimensional (3D) orthogonally woven composites. Two-dimensional (2D) laminated composites exhibit high in-plane stiffness and strength; however, they are inadequate in applications subjected to out-of-plane loads, particularly in engine fan blades, aircraft fuselage structures, and wind turbine blades. With an innovative approach, 3D orthogonally woven composites effectively overcome the limitations of traditional 2D laminates. The usage of 3D orthogonally woven composites in these structures can be beneficial because 3D orthogonally woven composites are more resistant to out-of-plane loading than 2D laminates, due to their improved mechanical properties through the thickness. In addition to this, improved impact damage tolerance, higher delamination resistance, and reduced assembly and production costs through single-piece fabric production are advantages of 3D orthogonally woven composites. 3D orthogonally woven composites, in spite of their advantages, present certain challenges in application. One of the significant challenges is the complex nature of their manufacturing process, which demands specialized equipment and skilled personnel, leading to high production costs. Their complex structure can also complicate design, analysis, and simulation, requiring advanced computational models. Additionally, the complex architecture of these composites can present challenges in repair and maintenance procedures. 3D orthogonally woven structures consist of three interwoven sets of yarns arranged in orthogonal directions, where the warp and weft yarns remain straight while the binder yarns interlace them to create a multidimensional architecture. This complex architecture of 3D orthogonally woven composites plays an important role in determining the mechanical properties of the structure. Since differences in cross-section configurations, yarn arrangements, and fiber interactions significantly influence the load-carrying capacity, stiffness, and overall performance of the composite, an in-depth examination of the structural architecture is critical to optimizing the mechanical properties of the material. Several analytical studies have examined the effects of binder-to-weft and binder-to-warp ratios on the elastic properties of 3D orthogonally woven composites. These analyses employ representative volume elements (RVEs) to model the material behaviors. The binder-to-weft ratio characterizes the number of wefts of yarn a binder yarn encircles before reversing direction within the weft layer. Similarly, the binder-to-warp ratio represents the proportion of warp yarns per layer relative to the total number of warps encompassed by the RVE. However, a key limitation of these existing studies is based on the absence of a comparative analysis between analytical solutions and numerical simulations. Furthermore, the impact of RVE thickness on its elastic coefficients has not been thoroughly investigated. Here, the effects of changing thickness on the tensile response of the structure, as obtained through analytical solutions and numerical simulations, are presented. Elastic constants of 3D fiber-reinforced composites were estimated using a multi-scale homogenization technique based on meso-macro homogenization with good correlation. Numerical simulations were performed using ABAQUS software to analyze the behavior of the models. Through the optimization of the geometrical parameters of RVE, 3D orthogonally woven composites can be effectively implemented across a diverse range of engineering applications, especially in the aviation field.