Experimental Studies on the Impact Response of 3D Fiberglass Fabric Subject to Different Size Impactors

摘要

The main objective of this study is to experimentally investigate the influence of impactor’s size on the impact response of a truly 3D fiberglass fabric (3DFGF). The 3DFGF is a new generation of 3D fiberglass fabric, recently introduced to the market. The 3DFGF consists of two bidirectional woven fabrics, which are knitted together by a vertical series of fiberglass fibers (pillars). The vertical fibers create hollow cavities in between the top and bottom fabrics. In order to maximize the mechanical response of the resin reinforced version of 3DFGF, the cavities can be filled with foams (polyurethane foam in this study). The resulting 3DFGFs exhibit an excellent response under both flexural and impact loadings. Moreover, the damage mechanism exhibited by this composite is markedly different from that produced by the conventional laminated fiberglass fabrics. In other words, the damage created in 3DFGFs remains as a local damage and does not propagate throughout the fabrics. Moreover, because of the unique structure of this 3DFGF, no delamination is developed within the fabric when subjected to an impact loading. One of the main intended applications of the introduced fabric is in the automotive applications, specifically for formation of auto-body components. It should be noted that vehicles experience different levels of impact loading in their life spans, caused by different shape obstacles; consequently, it is imperative to investigate the influence of impactor’s size on the response of this 3DFGF. For that, impactors with two different sizes (i.e., small-diameter and large-diameter hemispherical impactors) are considered in this investigation. Moreover, two different thickness of 3DFGF has been considered to study the influence of core thickness (or the overall structural stiffness) on their overall impact response. Force-time history, impact strength, maximum displacement and energy absorption capacity are presented and discussed for all tested specimens.