Interactive effects of p-aramid fabric structure and shear thickening fluid on impact resistance performance of soft armor materials

Kevlar fabrics treated with MTMS modified silica based STF showed better impact energy absorption as compared to APTES modified and control silica based STF treated fabrics, attributed to changes in interactions between fabrics and silica particles.

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Preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid for low-velocity impact resistance

Journal of Industrial Textiles ◽

10.1177/1528083720927013 ◽

2020 ◽

pp. 152808372092701 ◽

Cited By ~ 1

Author(s):

Wanli Xu ◽

Biao Yan ◽

Dongmei Hu ◽

Pibo Ma

Keyword(s):

Shear Rate ◽

Energy Absorption ◽

Impact Resistance ◽

Shear Thickening ◽

Weight Fraction ◽

Low Velocity Impact ◽

Impact Behavior ◽

Shear Thickening Fluid ◽

Spacer Fabric ◽

The Impact

This paper reports the preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid and studied its impact behavior under low-velocity impact loading. The shear thickening fluids have been prepared by mechanically dispersing 12 nm silica particles with weight fraction of 10, 15, 20, and 25% in various carriers (PEG200, PEG400, and PEG600). Rheological results indicate that shear thickening fluid experiences shear thickening transition at a specific shear rate. The critical shear rate reduces, and initial viscosity and maximum viscosity increase with the increase of silica weight fraction. The higher molecular weight of polyethylene glycols can lead to lower critical shear rate. The impact process of composite under impact loading can be divided into three stages. The warp-knitted spacer fabric with different negative Poisson’s ratio has a significant effect on the impact behavior. The warp-knitted spacer fabric with better auxetic performance endows composite better impact resistance, the specific performance is the deformation depth, and energy absorption and peak load increase with the increase of auxetic effect of fabric. The silica weight fraction of shear thickening fluid can increase the energy absorption of composite due to the shear thickening transition of shear thickening fluid. Shear thickening fluid has a synergistic effect with the auxetic warp-knitted spacer fabric on impact resistance of composite. The various carriers have no obvious influence on the overall energy absorption and impact load of composites.

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Rheological response and quasi-static stab resistance of STF/MWCNTs-impregnated aramid fabrics with different textures

Journal of Industrial Textiles ◽

10.1177/1528083719830144 ◽

2019 ◽

Vol 50 (3) ◽

pp. 380-397

Author(s):

Ting-Ting Li ◽

Xixi Cen ◽

Haokai Peng ◽

Haitao Ren ◽

Lianhe Han ◽

...

Keyword(s):

Tensile Strength ◽

Shear Thickening ◽

Critical Shear Rate ◽

Shear Thickening Fluid ◽

Aramid Fabric ◽

Stab Resistance ◽

Multi Walled Carbon Nanotubes ◽

Aramid Fabrics ◽

Self Protection ◽

Walled Carbon Nanotubes

Terrorist attacks occur constantly, which subsequently arouses awareness of self-protection. In order to alleviate the harm caused by sharp objects of knives and daggers, a design of flexible stab-resistant materials that are impregnated with the shear thickening fluid (STF)/multi-walled carbon nanotubes (MWCNTs) system and different texture of fabrics is presented. STF/MWCNTs are composed of polyethylene glycol (PEG 200) as the dispersion medium and silica (SiO2) of 12 nm and 75 nm as disperse phase as well as MWCNTs as supplementary reinforcement, in expectation to provide the aramid fabrics with high strengths, low critical shear rate, and a short thickening response time. The textures of aramid fabrics—plain (P), twill (T), satin (S), or basket (B) weave—are saturated in the STF/MWCNTs system. The synergetic influences of silica size and texture on tensile strength, quasi-static knife, and spike stab resistances of the STF/MWCNTs-impregnated aramid fabrics are examined. Results show that the plain aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2(SM12) exhibit the maximum tensile strength and quasi-static knife stab resistance, 14.7 MPa and 8.9 MPa, respectively, which is 1.15 and 1.43 times higher than pure aramid fabrics. Moreover, the basket-weave aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2have the maximum quasi-static spike stab resistance of 17.12 MPa compared to other textures of fabrics, which is 1.05 times higher than those immersed in the 75 nm SiO2STF/MWCNTs (SM75) system and 1.33 times higher than that of pure basket aramid fabrics.

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