The influences of rheological property on the impact performance of kevlar fabrics impregnated with SiO2/PEG shear thickening fluid
The influences of rheological property on the impact performance of kevlar fabrics impregnated with SiO2/PEG shear thickening fluid
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DOI：
10.1016/j.tws.2020.106717
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发表时间：
2020-06
影响因子：
6.4
通讯作者：
Lulu Liu;Zongzhi Yang;Zhenhua Zhao;Liu Xu;Wei Chen
中科院分区：
文献类型：
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作者：
Lulu Liu;Zongzhi Yang;Zhenhua Zhao;Liu Xu;Wei Chen
剪切增稠液 (STF) 已被证明在增强机织织物的抗冲击性能方面很有前景，可将其纳入航空发动机应用中的软壁密封外壳中。在当前的研究中，通过纱线拉拔和弹道冲击试验研究了具有明显不同剪切增稠行为的STF，以了解STF的流变行为与其增强抗冲击性的效果之间的关系，这为STF处理的软壁套管的设计提供了见解。采用直径为 100 和 650 nm 的球形 SiO2 颗粒来制备 STF，它们被称为 a 系统（100 nm 颗粒）和 b 系统（650 nm 颗粒）。研究了两个 STF 系统系列的流变特性。对于由 650 nm 二氧化硅颗粒组成的悬浮液系统，临界剪切率为 0.6–3.2 s−1，而对于 100 nm 颗粒组成的悬浮液系统，临界剪切率为 169–627 s−1。 Kevlar 织物浸渍了 STF，并使用钛叶片状弹丸对不同类型的 STF-Kevlar 和纯 Kevlar 织物进行了弹道冲击测试，以评估其在航空发动机密封应用中的抗冲击性。分析了能量吸收特性、变形特征和损伤模式。冲击测试结果表明，100 nm SiO2 制成的 STF 提高了 Kevlar 织物的抗冲击性能，能量吸收率提高了 56.6%，而 650 nm SiO2 制成的 STF 处理后则有所下降。两种悬浮体系的不同趋势归因于剪切速率与临界剪切速率的特定值。估计最大变形并与织物中形成的金字塔变形进行比较。与纯凯夫拉织物的松散结构相比，STF-凯夫拉织物在冲击下更加致密，并且作为一个整体结构。由于STF处理后纱线间摩擦作用增加，冲击过程中纱线滑移现象减少。对于用a系统STF处理的织物，主纱被拉伸并从机织织物的重叠结构中拉出，形成垂直条带区域，其失效模式涉及散开的纱线。 b系统STF处理织物的穿孔损伤集中在与叶片弹丸直接接触的区域，其中少量纱线断裂并被拉出。
Shear thickening fluids (STFs) have been proven promising in enhancing the anti-impact performance of woven fabric, which can be incorporated into soft-wall containment casing in aero-engine applications. In the current study, STFs having distinct different shear thickening behaviors were investigated through yarn pull-out and ballistic impact tests to understand the relationship between the rheological behavior of STFs and their effect in enhancing impact resistance, which provide insight into the design of STF-treated soft-wall casing. Spherical SiO2particles of diameters 100 and 650 nm were employed to prepare the STFs, which were referred to as a-system (100 nm particles) and b-system (650 nm particles). The rheological properties were investigated for two STF system series. The critical shear rate is 0.6–3.2 s−1for a suspension system composed of 650 nm silica particles, whereas the critical shear rate is 169–627 s−1for that of 100 nm particles. Kevlar fabrics were impregnated with STFs, and ballistic impact tests were conducted on different types of STF–Kevlar and neat Kevlar fabrics using titanium blade-like projectiles to evaluate their impact resistances in aero-engine containment applications. Energy absorption characteristics, deformation features, and damage patterns are analyzed. Impact test results show that the STF made of 100 nm SiO2improved the anti-impact performance of the Kevlar fabric and increased the energy absorption up to 56.6%, whereas it decreased in the treatment by STFs made of 650 nm SiO2. The different trends of the two suspension systems are attributed to the specific value of shear rate with critical shear rate. The maximum deformation is estimated and compared with the pyramid deformation formed in the fabric. The STF–Kevlar fabrics under impact are more compact and act as an integrated structure compared with the loose structure of neat Kevlar fabrics. Owing to the increased interyarn friction action after the STF treatment, less yarn slippage occurred during the impact. For fabrics treated with the a-system STF, primary yarns were stretched and pulled out from the overlap structure of the woven fabric, forming perpendicular strip areas with failure modes involving unraveled yarns. The perforated damage of the b-system-STF-treated fabrics is concentrated at the area directly in contact with the blade projectile, in which a small amount of yarns fractured and pulled out.