Characterization of the Mechanical and Impact Response of a New-Generation 3D Fiberglass Fabric

Abstract

The main objective of the present study is to characterize the mechanical behavior and impact response of a recently developed 3D woven/braided fiberglass fabric. The 3D-fiberglass fabric (3DFGF) consists of two bi-directional woven fabrics, knitted together by vertical braided glass fiber pillars. In addition to, or instead of glass fibers, carbon and even basalt fibers, as well as hybridizations of these fibers, could be used to form such 3D clothes. The unique configuration of fibers in this particular 3DFGF provides outstanding impact resistance to panels formed by this fabric. Moreover, the two bi-directional woven fabrics of 3DFGF create hollow core regions, surrounded by vertical glass pillars, which could be filled with a foam, thus further enhancing the resilience of the panel. The weakest link in any fiber-reinforced plastic (FRP) laminates is the interlaminar shear properties of the FRP, thus making them susceptible to impact loading. However, owing to the unique and resilient configuration of fibers in this new generation of 3DFGF, delamination type failure is seldom experienced by 3DFGFs. Moreover, to the best of authors’ knowledge, there has been no investigation characterizing the impact response of such 3DFGFs. Three-point bending and flatwise compressive tests with two different core thicknesses are conducted in two principal directions of 3DFGF to investigate its mechanical behavior. For each specimen and thickness, two different configurations are considered: (i) panels with their hollow core cavities filled with a foam, and (ii) panels without foam. Moreover, the low-velocity impact (LVI) response and failure modes of this new fabric are also investigated experimentally and also by computational simulations. The latter is done to address the clear lack of a robust computational framework by which one could predict the response of such 3DFGFs. Therefore, a major part of this study deals with predicting the behavior of such a complex 3D materials configuration by the finite-element method, using a commercial code (the ABAQUS). It will be demonstrated that the good agreementobtained between the experimental and simulation results would render the adopted framework as an effective and reliable means for predicting and optimizing the response of such 3DFGFs subject to complex loading conditions.