| [Boron-related materials, preparation, structure and application] Influence of Adhesive Layer on Ballistic Performance of Ceramic-based Armour Systems Influence of Adhesive Layer on Ballistic Performance of Ceramic-based Armour Systems Chun Li1; Saleema Noormohammed Noormohammed2; Yadienka Martinez Rubi1; Geneviève Toussaint3; Behnam Ashrafi4; Michael Jakubinek1; 1NATIONAL RESEARCH COUNCIL CANADA, Ottawa, Canada; 2NATIONAL RESEARCH COUNCIL CANADA, Saguenay, Canada; 3DEFENCE RESEARCH AND DEVELOPMENT CANADA, Valcartier, Canada; 4NATIONAL RESEARCH COUNCIL CANADA, Montreal, Canada; PAPER: 28/Nanomaterials/Regular (Oral) SCHEDULED: 16:45/Sat. 26 Oct. 2019/Ambrosia B (77/RF) ABSTRACT: In addition to ballistic penetration performance and blast survivability, weight has been one of the key drivers for modern armour system design [1-5]. Excessive weight of traditional metallic armour not only affects armour vehicles’ fuel efficiency, but also affects their deployability and mobility. Hybrid armour systems, made of ceramic strike face with metallic or composite backing, deliver an efficient solution by combining the light weight, high ballistic resistance of ceramics with ductility of the backing. This confines the ceramic fragment and absorbs the kinetic energy of the projectile. The primary approach to combine the ceramic strike face and backing is the use of adhesives. Knowledge of the influence of the adhesive properties on target damage, deformation and the ballistic resistance is of importance for composite armor design [1]. Optimization of adhesive selection and design could potentially increase survivability and reduce weight of ceramic-based armour systems. This study investigated the effect of adhesive layers on the ballistic performance of ceramic based armour, which was adhesively bonded onto a Kevlar composite backing. The influence of two classes of commonly used adhesive systems, a polyurethane and an epoxy-based adhesive, as well as that of a nanomaterial-modified polyurethane adhesive were investigated. Polyurethane based adhesive systems are more ductile than epoxy, but they often exhibit lower stiffness and strengths. Epoxy systems, on the other hand, are less ductile, but the usage of epoxy could lead to much improved acoustic impendence matching with ceramics. This allows increased energy transmission from the ceramic to the adhesive; hence the ceramic is less likely to fail [2-4]. The newly developed nanomaterial-modified polyurethane adhesive allowed for enhancement of stiffness, strength and acoustic impedance without significantly sacrificing other properties such as toughness and ductility of the base adhesive [5]. This study demonstrated that adhesive properties, in particular ductility and acoustic impedance, had a significant impact on ballistic performance. In spite of the advantages of the studied epoxy system of better stiffness, strength and acoustic impedance matching over polyurethane, the ceramic armour bonded with the epoxy was prone to disbonding at ceramic/Kevlar interface. Ballistic performance is also reduced as a result of low toughness and ductility. The effect of adhesive thickness was also found to be important for ballistic performance in past studies [6-8]. Thus, with regards to performance under ballistic impact, it was also investigated that increased elongation, along with the increase of adhesive thickness did not enhance multi-hit ballistic performance for the studied configuration. The usage of the nanomaterial-modified adhesive, with increased stiffness, strength, and adequate toughness, was promising to enhance the ballistic performance of ceramic-based armour. References: [1] W. Seifert, E. Strassburger, S. Grefen, S. Schaare, Experimental study about the influence of adhesive stiffness to the bonding strengths of adhesives for ceramic/metal targets, Defence Technology 12 (2016) 188-200 [2] R. Zaera, S. Sanchez-Saez, JL. Perez-Castellanos, C. Navarro, Modelling of adhesive layer in mixed ceramic/metal armours subjects to impact. Composites A Appl Sci Manuf 2000;31:823-33. [3] A.J. Harris, B. Vaughan, J.A. Yeomans, P.A. Smith and S.T. Burnage, Journal of the European Ceramic Society 33 (2013) 2925. [4] W. Seifert, E. Strassburger, S. Grefen, S. Schaare, Experimental study about the influence of adhesive stiffness to the bonding strengths of adhesives for ceramic/metal targets, Defence Technology 12 (2016) 188-200. [5] Rubi, Yadienka Martinez; Ashrafi, Behnam; Jakubinek, Michael B.; Zou, Shan; Laqua, Kurtis; Barnes, Michael; Simard, Benoit, Fabrication of high content carbon nanotube-polyurethane sheets with tailorable properties, ACS Appl. Mater. Interfaces (2017) 9, 36, 30840-30849. [6] S. Noormohammed, C. Li, S. Nikumb, Adhesive bonding of ceramic-based armor system, NATO STO AVT-266 Specialists- Meeting-Use of Bonded Joints in Military Applications, Torino, Italy, April 16-17, 2018 [7] J. Lopez-Puente, A. Arias, C. Zaera, C. Navarro, The effect of the thickness of the adhesive layer on the ballistic limit of ceramic/metal armours. An experimental and numerical study. Int J Impact Eng 2005;32:321-36. [8] A. Prakash, J. Rajasankar, N. Anandavalli, M. Verma, NR. Iyer, Influence of adhesive thickness on high velocity impact perfomance of ceramic/metal |
