The ballistic performance of aramid based fabrics impregnated with multi-phase shear thickening fluids

2017 ◽  
Vol 64 ◽  
pp. 296-306 ◽  
Author(s):  
Selim Gürgen ◽  
Melih Cemal Kuşhan
2015 ◽  
Vol 782 ◽  
pp. 153-157 ◽  
Author(s):  
Yan Wang ◽  
Shu Kui Li ◽  
Xin Ya Feng

This study investigates the ballistic penetration performance of aramid fabric impregnated with shear thickening fluid. The ballistic test was conducted at impact velocity of 445 m/s, and three types of shear thickening fluids prepared with silica particles of different sizes (200nm, 340nm and 480nm) are involved. The results demonstrate an enhancement in ballistic properties of fabric due to the impregnation of shear thickening fluids. The fabrics with smaller particle size show better ballistic performance. Microscopic observation of aramid fabric reveals that shear thickening fluids with smaller silica particles have a better adhesion on and between yarns, enhancinging the coupling effect between yarns. The corresponding mechanism was discussed in the paper.


2017 ◽  
Vol 31 (3) ◽  
pp. 392-407 ◽  
Author(s):  
A Khodadadi ◽  
GH Liaghat ◽  
AR Sabet ◽  
H Hadavinia ◽  
A Aboutorabi ◽  
...  

This study presents the high-velocity impact performance of a composite material composed of woven Kevlar fabric impregnated with a colloidal shear thickening fluids (STFs). Although the precise role of the STF in the high-velocity defeat, process is not exactly known but it is suspected to be due to the increased frictional interaction between yarns in impregnated fabrics. In order to explore the mechanism of this enhanced energy absorption, high-velocity impact test was conducted on neat, impregnated fabric and also on pure STF without fabric. A finite element model has been carried out to consider the effect of STF impregnation on the ballistic performance. For this purpose, fabric was modeled using LS-DYNA by employing the experimental results of yarn pull-out tests to characterize the frictional behavior of the STF impregnated fabric. The simulation result is a proof that the increased performance for STF impregnated Kevlar fabric is due to the increased friction.


Author(s):  
Fardin Khalili ◽  
Federico De Paoli ◽  
Rasim Guldiken

Since the creation of advanced knives and firearms with high rates of speed, safety has always been a vital issue for armed forces. A disadvantage of a regular fabric Kevlar is that, although it has an effective resistance against the impact of low-speed bullets, it reveals its weakness in the case of a stab wound and high-speed bullets. Under these circumstances, a new executable technology of fibers that improves the ballistic performance of the materials utilized in body armors is an essential necessity to build high quality and protective vests which are perfectly bulletproof. The purpose of this study is to investigate the physics and concepts of shear thickening fluids and perform a computational CFD simulation of liquid body armors which consist of a combination of polyethylene glycol liquid and nanoparticles of silica. A model of multiphase flow environment with STFKevlar, as a representative of the non-Newtonian shear thickening fluid (STF), is simulated in STAR-CCM+ in order to analyze the behavior of STFs under impact and performance of novel liquid body armors. In the current simulation, Eulerian multiphase flow and volume of fluid (VOF) are applied to generate three discrete regions and determine the volume fraction of each phase including gas, non-Newtonian liquid and solid which represent air, STFKevlar and bullet, respectively. Moreover, dynamic fluid body interactions (DFBI) and overset mesh are utilized to consider the interactions between the regions and forces applied. In this study, the properties of the bullet are based on characteristics of a regular pistol bullet, and it approaches the STFKevlar with the constant speed of 400 m/s. The results show that the non-Newtonian material is initially at equilibrium state and while the bullet approaches the STFKevlar, it acts like a shear thinning fluid. As a high-speed bullet nears the STFKevlar, it absorbs the significant amount of energy that is applied by the bullet. Consequently, the bullet stops penetrating the STFKevlar in a very small fraction of time due to the considerable increase in viscosity. As the shear rate increases over a certain critical value, viscosity increases remarkably which is the main characteristic of shear thickening transition and finally, it reaches to its maximum value of viscosity in approximately 8 × 10−5sec. In addition, a bullet applies a considerable amount of force on any Kevlar due to its high velocity and kinetic energy; however, the high resistant STFKevlar is approved as a high quality and protective vests which stops the bullet in 6 × 10−4sec.


2019 ◽  
Vol 64 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Balasubrahmanya Harish Manukonda ◽  
Victor Avisek Chatterjee ◽  
Sanjeev Kumar Verma ◽  
Debarati Bhattacharjee ◽  
Ipsita Biswas ◽  
...  

The ballistic resistance of high-strength fabrics improves upon impregnation with Shear Thickening Fluids (STFs). The performance of such STF treated fabrics depends on the rheological properties of the STF which in turn are governed by the physicochemical properties of the STF. The present study utilizes rheological characterization of shear thickening silica-polyethylene glycol dispersions (of different material configurations in terms of packing fraction, particle size and continuous phase viscosity) to assess their performance and obtain the best STF material configuration for ballistic body armor applications based on the design criteria proposed herein. The ballistic performance assessment results showed that the STFs with high packing fractions which thicken discontinuously, are highly effective compared to the continuously shear thickening fluids. Furthermore, the use of smaller particle size dispersed phase in the STF formulation was determined to be economical. Also, the use of lower molecular weight dispersion medium was suggested as it allows for a broader working temperature range of the STF. Additionally, the technological issues associated with the development and the practical application of STF-Armor were addressed.


2011 ◽  
Vol 4 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Jie Ding ◽  
Weihua Li ◽  
Shirley Z. Shen

2021 ◽  
pp. 002199832098424
Author(s):  
Mohsen Jeddi ◽  
Mojtaba Yazdani

Whereas most previous studies have focused on improving the penetration resistance of Shear Thickening Fluids (STFs) treated composites, in this study, the dynamic compressive response of single and multi-ply 3 D E-Glass Fiber Reinforced Polymer (GFRP) composites with the STF matrix was investigated by using a drop-weight low-velocity impact test. The experimental results revealed the STF improved the compressive and cushioning performance of the composites such that with increasing its concentration, further improvement was observed. The five-ply composite containing the STF of 30 wt% silica nanoparticles and 1 wt% carbon nanotubes (CNTs) reduced the applied peak force by 56% and 26% compared to a steel plate and five-ply neat samples, respectively. A series of repeated impacts was performed, and it was found that the performance of high-concentration composites is further decreased under this type of loading.


Sign in / Sign up

Export Citation Format

Share Document