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 ofimpactor’s size on the impact response of a truly 3D fiberglass fabric (3DFGF). The3DFGF 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 bya vertical series of fiberglass fibers (pillars). The vertical fibers create hollow cavities inbetween the top and bottom fabrics. In order to maximize the mechanical response ofthe resin reinforced version of 3DFGF, the cavities can be filled with foams(polyurethane foam in this study). The resulting 3DFGFs exhibit an excellent responseunder both flexural and impact loadings. Moreover, the damage mechanism exhibitedby this composite is markedly different from that produced by the conventionallaminated fiberglass fabrics. In other words, the damage created in 3DFGFs remains asa local damage and does not propagate throughout the fabrics. Moreover, because of theunique structure of this 3DFGF, no delamination is developed within the fabric whensubjected to an impact loading.One of the main intended applications of the introduced fabric is in the automotiveapplications, specifically for formation of auto-body components. It should be notedthat vehicles experience different levels of impact loading in their life spans, caused bydifferent shape obstacles; consequently, it is imperative to investigate the influence ofimpactor’s size on the response of this 3DFGF. For that, impactors with two differentsizes (i.e., small-diameter and large-diameter hemispherical impactors) are consideredin this investigation. Moreover, two different thickness of 3DFGF has been consideredto study the influence of core thickness (or the overall structural stiffness) on theiroverall impact response. Force-time history, impact strength, maximum displacementand energy absorption capacity are presented and discussed for all tested specimens.