In this study, the ballistic impact behavior of auxetic sandwich composite human body armor was analyzed using finite element analysis. The auxetic core of the armor was composed of discrete re-entrant unit cells. The sandwich armor structure consisted of a front panel of aluminum alloy (Al 7075-T6), UHMWPE (sandwich core), and a back facet of silicon carbide (SiC) bonded together with epoxy resin. Numerical simulations were run on Explicit Dynamics/Autodyne 3-D code. Various projectile velocities with the same boundary conditions were used to predict the auxetic armor response. These results were compared with those of conventional monolithic body armor. The results showed improved indentation resistance with the auxetic armor. Deformation in auxetic armor was observed greater for each of the cases when compared to the monolithic armor, due to higher energy absorption. The elastic energy dissipation results in the lower indentation in an auxetic armor. The armor can be used safely up to 400 m/s; being used at higher velocities significantly reduced the threat level. Conversely, the conventional monolithic modal does not allow the projectile to pass through at a velocity below 300 m/s; however, the back face becomes severely damaged at 200 m/s. At a velocity of 400 m/s, the front facet of auxetic armor was destroyed; however, the back facet was completely safe, while the monolithic panel did not withstand this velocity and was completely damaged. The results are encouraging in terms of resistance offered by the newly adopted auxetic armor compared to conventional monolithic armor.

Department of Mechanical Engineering International Islamic University Islamabad 44000 Pakistan

Institute for Nanomaterials Advanced Technologies and Innovation Studentska 2 461 17 Liberec Czech Republic

Technical University of Liberec Studentska 2 461 17 Liberec Czech Republic

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Ren X., Das R., Tran P., Ngo T.D., Xie Y.M. Auxetic metamaterials and structures: A review. Smart Mater. Struct. 2018;27:023001. doi: 10.1088/1361-665X/aaa61c. DOI

Farokhi Nejad A., Alipour R., Shokri Rad M., Yazid Yahya M., Rahimian Koloor S.S., Petrů M. Using finite element approach for crashworthiness assessment of a polymeric auxetic structure subjected to the axial loading. Polymers. 2020;12:1312. doi: 10.3390/polym12061312. PubMed DOI PMC

Funari M.F., Spadea S., Lonetti P., Lourenço P.B. On the elastic and mixed-mode fracture properties of PVC foam. Theor. Appl. Fract. Mech. 2021;112:102924. doi: 10.1016/j.tafmec.2021.102924. DOI

Evans K.E., Alderson A. Auxetic materials: Functional materials and structures from lateral thinking! Adv. Mater. 2000;12:617–628. doi: 10.1002/(SICI)1521-4095(200005)12:9<617::AID-ADMA617>3.0.CO;2-3. DOI

Zochowski P., Bajkowski M., Grygoruk R., Magier M., Burian W., Pyka D., Bocian M., Jamroziak K. Ballistic impact resistance of bulletproof vest inserts containing printed titanium structures. Metals. 2021;11:225. doi: 10.3390/met11020225. DOI

Greaves G., Greer A., Lakes R., Rouxel T. Poisson′s ratio and modern materials (vol 10, pg 823, 2011) Nat. Mater. 2019;18:406. doi: 10.1038/s41563-019-0319-2. PubMed DOI

Assidi M., Ganghoffer J.-F. Composites with auxetic inclusions showing both an auxetic behavior and enhancement of their mechanical properties. Compos. Struct. 2012;94:2373–2382. doi: 10.1016/j.compstruct.2012.02.026. DOI

Rahimian Koloor S.S., Karimzadeh A., Yidris N., Petrů M., Ayatollahi M.R., Tamin M.N. An energy-based concept for yielding of multidirectional FRP composite structures using a mesoscale lamina damage model. Polymers. 2020;12:157. doi: 10.3390/polym12010157. PubMed DOI PMC

Ha N.S., Lu G. A review of recent research on bio-inspired structures and materials for energy absorption applications. Compos. Part B Eng. 2020;181:107496. doi: 10.1016/j.compositesb.2019.107496. DOI

Prawoto Y. Seeing auxetic materials from the mechanics point of view: A structural review on the negative Poisson’s ratio. Comput. Mater. Sci. 2012;58:140–153. doi: 10.1016/j.commatsci.2012.02.012. DOI

Alderson A., Alderson K. Expanding materials and applications: Exploiting auxetic textiles. Tech. Text. Int. 2005;777:29–34.

Allen T., Martinello N., Zampieri D., Hewage T., Senior T., Foster L., Alderson A. Auxetic Foams for Sport Safety Applications. Procedia Eng. 2015;112:104–109. doi: 10.1016/j.proeng.2015.07.183. DOI

Vo N.H., Pham T.M., Hao H., Bi K., Chen W., San Ha N. Blast resistant enhancement of meta-panels using multiple types of resonators. Int. J. Mech. Sci. 2022;215:106965. doi: 10.1016/j.ijmecsci.2021.106965. DOI

Cantwell W.J., Morton J. The impact resistance of composite materials—A review. Composites. 1991;22:347–362. doi: 10.1016/0010-4361(91)90549-V. DOI

Oliveira M.J., Gomes A.V., Pimenta A.R., da Silva Figueiredo A.B.-H. Alumina and low density polyethylene composite for ballistics applications. J. Mater. Res. Technol. 2021;14:1791–1799. doi: 10.1016/j.jmrt.2021.07.069. DOI

Nyanor P., Hamada A.S., Hassan M.A.-N. Ballistic Impact Simulation of Proposed Bullet Proof Vest Made of TWIP Steel, Water and Polymer Sandwich Composite Using FE-SPH Coupled Technique. Key Eng. Mater. 2018;786:302–313. doi: 10.4028/www.scientific.net/KEM.786.302. DOI

Pacek D., Rutkowski J. The composite structure for human body impact protection. Compos. Struct. 2021;265:113763. doi: 10.1016/j.compstruct.2021.113763. DOI

Soydan A.M., Tunaboylu B., Elsabagh A.G., Sarı A.K., Akdeniz R. Simulation and experimental tests of ballistic impact on composite laminate armor. Adv. Mater. Sci. Eng. 2018;2018:4696143. doi: 10.1155/2018/4696143. DOI

Kant S., Verma S.L. A review on analysis and design of bullet resistant jacket-ballistic analysis. Int. Adv. Res. J. Sci. Eng. Technol. 2017;4:71–80.

Abdi B., Koloor S., Abdullah M., Amran A., Yahya M.Y. Applied Mechanics and Materials. Trans Tech Publications Ltd.; Frienbach, Switzerland: 2012. Effect of strain-rate on flexural behavior of composite sandwich panel; pp. 766–770.

San Ha N., Lu G., Xiang X. Energy absorption of a bio-inspired honeycomb sandwich panel. J. Mater. Sci. 2019;54:6286–6300.

Ingrole A., Hao A., Liang R. Design and modeling of auxetic and hybrid honeycomb structures for in-plane property enhancement. Mater. Des. 2017;117:72–83. doi: 10.1016/j.matdes.2016.12.067. DOI

Vo N.H., Pham T.M., Bi K., Chen W., Hao H. Stress Wave Mitigation Properties of Dual-meta Panels against Blast Loads. Int. J. Impact Eng. 2021;154:103877. doi: 10.1016/j.ijimpeng.2021.103877. DOI

Imbalzano G., Tran P., Ngo T.D., Lee P.V.S. A numerical study of auxetic composite panels under blast loadings. Compos. Struct. 2016;135:339–352. doi: 10.1016/j.compstruct.2015.09.038. DOI

Imbalzano G., Tran P., Ngo T.D., Lee P.V. Three-dimensional modelling of auxetic sandwich panels for localised impact resistance. J. Sandw. Struct. Mater. 2017;19:291–316. doi: 10.1177/1099636215618539. DOI

Imbalzano G., Tran P., Lee P.V., Gunasegaram D., Ngo T.D. Applied Mechanics and Materials. Trans Tech Publications Ltd.; Frienbach, Switzerland: 2016. Influences of material and geometry in the performance of auxetic composite structure under blast loading; pp. 476–481.

Imbalzano G., Linforth S., Ngo T.D., Lee P.V.S., Tran P. Blast resistance of auxetic and honeycomb sandwich panels: Comparisons and parametric designs. Compos. Struct. 2018;183:242–261. doi: 10.1016/j.compstruct.2017.03.018. DOI

Burlayenko V.N., Sadowski T. Simulations of post-impact skin/core debond growth in sandwich plates under impulsive loading. J. Appl. Nonlinear Dyn. 2014;3:369–379. doi: 10.5890/JAND.2014.12.008. DOI

Linforth S.J. Ph.D. Thesis. The University of Melbourne; Melbourne, Australia: 2020. Auxetic Armour System for Protection against Soil Blast Loading.

Novak N., Starčevič L., Vesenjak M., Ren Z. Blast and Ballistic Loading Study of Auxetic Composite Sandwich Panels with LS-DYNA. 2019. [(accessed on 29 December 2021)]. Available online: https://www.semanticscholar.org/paper/Blast-and-ballistic-loading-study-of-auxetic-panels-Novak-Star%C4%8Devi%C4%8D/cb928c507ac0fbac28a180e6caab555201cced39.

Yang S., Qi C., Wang D., Gao R., Hu H., Shu J. A Comparative Study of Ballistic Resistance of Sandwich Panels with Aluminum Foam and Auxetic Honeycomb Cores. Adv. Mech. Eng. 2015;5:589216. doi: 10.1155/2013/589216. DOI

Zhang D.-N., Shangguan Q.-Q., Xie C.-J., Liu F. A modified Johnson–Cook model of dynamic tensile behaviors for 7075-T6 aluminum alloy. J. Alloys Compd. 2015;619:186–194. doi: 10.1016/j.jallcom.2014.09.002. DOI

Figueiredo A.B.-H.d.S., Lima É.P., Gomes A.V., Melo G.B.M.d., Monteiro S.N., Biasi R.S.d. Response to ballistic impact of alumina-UHMWPE composites. Mater. Res. 2018;21:2–4. doi: 10.1590/1980-5373-mr-2017-0959. DOI

Rahbek D.B., Simons J.W., Johnsen B.B., Kobayashi T., Shockey D.A. Effect of composite covering on ballistic fracture damage development in ceramic plates. Int. J. Impact Eng. 2017;99:58–68. doi: 10.1016/j.ijimpeng.2016.09.010. DOI

Yamini S., Young R.J. The mechanical properties of epoxy resins. J. Mater. Sci. 1980;15:1823–1831. doi: 10.1007/BF00550603. DOI

Wang X., Shi J. Validation of Johnson-Cook plasticity and damage model using impact experiment. Int. J. Impact Eng. 2013;60:67–75. doi: 10.1016/j.ijimpeng.2013.04.010. DOI

Koloor S., Tamin M. Effects of lamina damages on flexural stiffness of CFRP composites; Proceedings of the 8th Asian-Australasian Conference on Composite Materials; Kuala Lumpur, Malaysia. 6–8 November 2012.

Zhang Y., Outeiro J., Mabrouki T. On the selection of Johnson-Cook constitutive model parameters for Ti-6Al-4 V using three types of numerical models of orthogonal cutting. Procedia Cirp. 2015;31:112–117. doi: 10.1016/j.procir.2015.03.052. DOI

Johnson G.R., Cook W.H. Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures. Eng. Fract. Mech. 1985;21:31–48. doi: 10.1016/0013-7944(85)90052-9. DOI

Johnson G.R. A constitutive model and data for materials subjected to large strains, high strain rates, and high temperatures; Proceedings of the 7th International Symposium of Ballistics; The Hague, The Netherlands. 19–21 April 1983; pp. 541–547.

Brar N., Joshi V., Harris B. Aip Conference Proceedings. American Institute of Physics; University Park, MD, USA: 2009. Constitutive model constants for Al7075-t651 and Al7075-t6; pp. 945–948.