Original Article Impact evaluation of Kevlar-based angle-interlock woven textile composite structures Bilal Zahid 1,2 and Xiaogang Chen 2 Abstract This article is a part of the research investigating the impact evaluation of angle-interlock woven Kevlar-based composite structures. The research work focuses on energy absorption and force attenuation. This study was conducted in order to understand the behaviour of the fabric layering effect on composite properties and the effect of layering orientation in multilayer composites. In this article, Kevlar-based textile composite structures having angle-interlock weave were developed using vacuum bagging technique and impact tests were carried out on the drop weight impact testing instrument. The result shows that the thickness plays a vital role in energy absorption and force transmission capabilities. Keywords Angle interlock, composite, vacuum bagging, energy absorption, force attenuation, force transmission, drop weight impact Research background The matrix phase (resin) and the reinforcement phase (fabric) are the building blocks for a composite mater- ial. In this study, angle-interlock (AI) fabric has been used as the reinforcement phase and thermoset epoxy resin was used as the matrix phase. The physical and mechanical properties of the developed composite structures from five-layer AI fabric has been calculated and analysed. 1 Special five-layer AI fabric was made and single piece textile reinforced helmet shells were successfully developed using modified vacuum bag- ging. 2 Fabric layering and layering orientation are sig- nificant factors that can impact the performance of the composite panels. For this reason, in this study, the fabric layering effect and the layering orientation are studied based on force attenuation and energy absorption. Manufacturing of AI fabric AI fabric is one of the three-dimensional fabrics; it usu- ally consists of interlocking binder warp yarns, straight aligned weft yarns and optional wadding warp yarns, 3 as shown in Figure 1. 4 Due to its good inherent mouldable properties, AI fabrics are used in making helmet shells. 2,5 In this study, ‘through the thickness’ AI fabric has been used and manufactured on conventional shuttle loom – ‘Arbon 100 W’ made by Adolf Saurer TM . Kevlar Õ (Aramid) roving type 49 supplied by DuPont TM is used in both warp and weft yarns. The manufactured fabric has a construction of 5-8-28 AI weave, i.e. 5 layers of weft yarns, 8 ends/cm and 28 picks/cm. The properties of the Kevlar are listed in Table 1. 6 1 Textile Engineering Department, NED University of Engineering and Technology, Karachi, Sindh, Pakistan 2 The University of Manchester, Manchester, United Kingdom Corresponding author: Bilal Zahid, Textile Engineering Department, NED University of Engineering and Technology, Karachi 75270, Sindh, Pakistan. Email: drbilalzahid@neduet.edu.pk Journal of Reinforced Plastics and Composites 32(12) 925–932 ! The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0731684413480006 jrp.sagepub.com by Bilal Zahid on February 10, 2015 jrp.sagepub.com Downloaded from