Copyright © 2018 Authors. This is an open access article distributed under the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology, 7 (4.14) (2018) 449-453 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research paper Impact Resistance of 3D Woven Composites Impacted by Different Impactor Shapes D.P.C. Aiman 1 , M.F. Yahya 2 *, M.R. Ahmad 3 , S.A. Ghani 4 Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan *Corresponding author E-mail: mfy@salam.uitm.edu.my Abstract The aim of this study was to investigate impact resistance of 3D woven composites, impacted by three different impactor shapes. An experimental study was carried out to compare the impact resistance on four types of 3D woven fiberglass composites. Impact resistance test will be performed using standard method ASTM D2444, with a set up initial impact energy is 20 J, velocity of 3.4901 m/s, height of 0.6163m and mass applied is 3.29 kg. Three different impactor shapes which are hemispherical, conical and ogival were used for testing woven fabric composite impact test. Hand lay-up technique was used to fabricate the composites. From results, 4 float Layer-to-layer Interlock (4L) gave the highest impact resistance for all impactor shapes with 6258.0 N for hemispherical impactor, 4000.1 N for conical impactor and 3750.7 N for ogival impactor. Ogival impactor tends to penetrate the woven composite samples better compared to conical and hemispherical impactors. Keywords: Woven composites, Impact resistance, Impactor shapes, Fiberglass, Low-velocity 1. Introduction Composite materials are made from combinations of two or more different substances with own characteristics, which then com- bined produced a superior material used for various applications [1]. Composites materials has developed progressively in a wide range of structural components over conventional materials be- cause of their better properties; such as strength-to-weight ratio, improved fatigue life, high strength and improved corrosion. 3D woven fabric are produced by interlacing of three sets of yarns that are warp yarn, weft yarn and z-yarn [2]. There are many textile structures being used for composites. The structures are woven, knitted, braided and yarns. Among all, wo- ven fabrics are one of the most importance structures used for composites. Woven fabrics are produced by assembling yarns in warp and weft directions. Weft and warp yarns are positioned next to each other depending on the yarn thickness. The position of the yarns should be emphasized as yarn friction contributed to woven fabric resistance against impact of puncture force [3]. Normally, the direction of yarns interlacing for 3D fabric struc- tures are longitudinal (X), cross (Y) and vertical (Z) [4]. During formation of 3D woven fabric, the z-yarn solidify the fabric by interconnecting the warp yarns and weft yarns through the thick- ness of the fabric [5]. 3D fabrics have developed rapidly to com- posite manufacturers as it offer better delamination resistance [6, 7]. 3D woven fabric can be produced by 3D and 2D weaving ma chines. Angle interlock and orthogonal weave are examples of 3D woven fabric. 3D angle interlock fabric is good for ballistic resistance. Zhjiang et al [8] stated that 3D angle interlock fabric suitable for applica- tions on ballistic protection because it have high delamination resistance than laminated composite and in-plane modulus. In addition, Vaidya et al [9] studied that 3D angle interlock compo- site have higher impact resistance due to able to absorb high ca- pacity of energy by the z-direction fibers. Orthogonal weave is another example 3D woven fabric. Orthogo- nal weave comprises of three sets of yarns that are warp, weft and stuffer yarns. All these yarns will be bind together by using binder yarn to enhance the structural integrity [10]. This binder yarn helps in improving high modulus, better shear and torsional strength to prevent delamination [11]. Previous study conducted by [12] stated that 3D orthogonal woven composites has a unique energy absorption mechanisms for low- velocity impact and gave the largest spread of damage. In addition, Xiwen Jia et al [13] studied about the ballistic penetration on 3D orthogonal woven composite using conical cylindrical steel pro- jectile. The study concluded that 3D orthogonal woven composite has a good impact resistance as no delamination occurs because of the existence of z-yarns in thickness direction. In this paper, the impact resistance of 3D woven fabric fiberglass composites when subjected to a drop weight impact loading is studied. This study was carried out for low-velocity impact load- ing. 2. Methodology Four types of 3D woven fiberglass fabrics were used for the re- search. The fabrics are 1-Float Angle Interlock (1A), 3-Float An- gle-Layer Interlock (3AL), 9-Float Angle Interlock (9A), and 4- Float Layer-to-Layer Interlock (4L). The cross sectional view of these fabrics are shown in Figure 1, Figure 2, Figure 3 and Figure 4. Epoxy Morcrete BJC39 and hardener HY225 were selected as matrix materials. Fiberglass reacts well with epoxy thus produced a strong and high mechanical performance composites. The prop- erties of Morcrete BJC 39 epoxy resin are shown in Table 1.