“…To measure the extent of impact energy absorption by a fabric sample, dynamic impact test was performed on CEAST Fractovis Plus drop tower impact tester shown in Figure 3 Figure 3. Drop tower impact tester. 23 , following ASTM D3763. Fabric samples of size 15 cm × 15 cm were taken and clamped at 7000 N force between two circular jaws with knurled surface and having 76 mm and 108 mm inner and outer diameters, respectively.…”
Section: Methodsmentioning
confidence: 99%
“…Currently, UHMWPE based armour materials have gained popularity owing to their lowest density (0.97 g/cm 3 ) amongst high-performance fibres, as well as excellent tensile properties. 21,22 Several researchers have reported judicious configuration of armour panels using UHMWPE UD laminates 23–25. Moving to surface modification for enhancement in impact resistance, by far, treatment with STF is the most popular and most researched upon.…”
Section: Introductionmentioning
confidence: 99%
“…36,37 However, most of the applications of STF on woven fabrics have revolved around the use of aramid woven fabrics as the base material 38–40. Besides, in most of the experimental and numerical studies, UHMWPE fibres have been used in UD laminate form 23–25 ,41,42 . Nevertheless, as far as the use of STF is concerned, woven fabrics are always better than their UD counterparts as the STF can penetrate in the interstices of filaments and yarns in case of the former and can get the trigger when the filaments and yarns move relative to each other during impact.…”
Section: Introductionmentioning
confidence: 99%
“…21,22 Several researchers have reported judicious configuration of armour panels using UHMWPE UD laminates. [23][24][25] Moving to surface modification for enhancement in impact resistance, by far, treatment with STF is the most popular and most researched upon. The non-Newtonian STFs 26 are known to transform from liquid to solid state upon impact, during which they absorb 27 and also help the fabric to dissipate considerable amount of impact energy.…”
Section: Introductionmentioning
confidence: 99%
“…[38][39][40] Besides, in most of the experimental and numerical studies, UHMWPE fibres have been used in UD laminate form. [23][24][25]41,42 Nevertheless, as far as the use of STF is concerned, woven fabrics are always better than their UD counterparts as the STF can penetrate in the interstices of filaments and yarns in case of the former and can get the trigger when the filaments and yarns move relative to each other during impact. Sun et al 43 and Gu et al 44 reported improvement in stab/spike resistance of UHMWPE woven fabrics after STF impregnation.…”
The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.
“…To measure the extent of impact energy absorption by a fabric sample, dynamic impact test was performed on CEAST Fractovis Plus drop tower impact tester shown in Figure 3 Figure 3. Drop tower impact tester. 23 , following ASTM D3763. Fabric samples of size 15 cm × 15 cm were taken and clamped at 7000 N force between two circular jaws with knurled surface and having 76 mm and 108 mm inner and outer diameters, respectively.…”
Section: Methodsmentioning
confidence: 99%
“…Currently, UHMWPE based armour materials have gained popularity owing to their lowest density (0.97 g/cm 3 ) amongst high-performance fibres, as well as excellent tensile properties. 21,22 Several researchers have reported judicious configuration of armour panels using UHMWPE UD laminates 23–25. Moving to surface modification for enhancement in impact resistance, by far, treatment with STF is the most popular and most researched upon.…”
Section: Introductionmentioning
confidence: 99%
“…36,37 However, most of the applications of STF on woven fabrics have revolved around the use of aramid woven fabrics as the base material 38–40. Besides, in most of the experimental and numerical studies, UHMWPE fibres have been used in UD laminate form 23–25 ,41,42 . Nevertheless, as far as the use of STF is concerned, woven fabrics are always better than their UD counterparts as the STF can penetrate in the interstices of filaments and yarns in case of the former and can get the trigger when the filaments and yarns move relative to each other during impact.…”
Section: Introductionmentioning
confidence: 99%
“…21,22 Several researchers have reported judicious configuration of armour panels using UHMWPE UD laminates. [23][24][25] Moving to surface modification for enhancement in impact resistance, by far, treatment with STF is the most popular and most researched upon. The non-Newtonian STFs 26 are known to transform from liquid to solid state upon impact, during which they absorb 27 and also help the fabric to dissipate considerable amount of impact energy.…”
Section: Introductionmentioning
confidence: 99%
“…[38][39][40] Besides, in most of the experimental and numerical studies, UHMWPE fibres have been used in UD laminate form. [23][24][25]41,42 Nevertheless, as far as the use of STF is concerned, woven fabrics are always better than their UD counterparts as the STF can penetrate in the interstices of filaments and yarns in case of the former and can get the trigger when the filaments and yarns move relative to each other during impact. Sun et al 43 and Gu et al 44 reported improvement in stab/spike resistance of UHMWPE woven fabrics after STF impregnation.…”
The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.
ZnO rice like nonarchitects are grafted on the graphene carbon core via a rapid microwave synthesis route. The prepared grafted systems are characterized via XRD, SEM, RAMAN, and XPS to examined the structural and morphological parameters. Zinc oxide grafted graphene sheets (ZnO‐G) are further doped in β‐phase of polyvinylidene fluoride (PVDF) to prepare the polymer nanocomposites (PNCs) via mixed solvent approach (THF/DMF). β‐phase confirmation of PVDF PNCs is done by FTIR studies. It is observed that ZnO‐G filler enhances the β‐phase content in the PNCs. Non‐doped PVDF and PNCs are further studied for rheological behavior under the shear rate of 1–100 s−1. Doping of ZnO‐G dopant to the PVDF matrix changes its discontinuous shear thickening (DST) behavior to continues shear thickening behavior (CST). Hydrocluster formation and their interaction with the dopant could be the reason for this striking DST to CST behavioral change. Strain amplitude sweep (10−3% ‐10%) oscillatory test reveals that the PNCs shows extended linear viscoelastic region with high elastic modulus and lower viscous modulus. Effective shear thickening behavior and strong elastic strength of these PNCs present their candidature for various fields including mechanical and soft body armor applications.
This study proposes a process for the preparation of composite laminates using the shear thickening fluid (STF) impregnated aramid fabric and presents some fabric panel configuration strategies. Firstly, this study prepared two kinds of STF using 20 nm and 500 nm silica particles. Then, the STF‐impregnated Kevlar fabrics were laminated and hot‐pressed to form the fabric panels. After that, the ballistic performance of the fabric panels was evaluated by firing the 9 mm steel core projectile using a gas gun. The ballistic tests showed that the ballistic performance of the hybridized configuration panels using STF‐20 treated fabrics as the front panels and STF‐500 treated fabrics as the backing panels was superior, with a reduction of 36.1%–37.6% in the number of perforated layers (4.7–5 layers) compared to a single STF‐treated panel. This study provides a new idea and method for applying STF in protective equipment.Highlights
Shear thickening fluid (STF) and aramid fabric are better combined by hot pressing lamination process;
The ballistic properties of fabric panels are significantly improved by hybrid configuration;
The ballistic performance enhancement mechanism of composite bulletproof plate was revealed.
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