Influences of a wide service-environment temperature range on the ballistic performance of STF-impregnated Kevlar

• Published in: Composite structures 2022-05, Vol.287, p.115330, Article 115330
• Main Authors: Zhihao, Xie, Xiaodi, Hou, Lulu, Liu, Wei, Chen, Zhenhua, Zhao, Gang, Luo
• Format: Article
• Language: English
• Subjects: Ballistic impact; Environmental temperature; Kevlar fabric; Picture-frame shear; Shear thickening fluid
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2022.115330

•The shear performance and the ballistic performance of STF-impregnated fabrics across a wide temperature range (−50 °C to 100 °C) are examined.•The maximum viscosity of 20 wt% STF increases dramatically with decreasing temperature, while the critical shear rate becomes very small.•Compared with room temperature (20 °C), both high- and low-temperature environments cause the shear performance and ballistic limit of STF-impregnated fabrics to decrease.•Combined with the analysis of the energy absorption of the fabrics, the elongation at failure of the yarn and fiber breaking micro morphology, the influence mechanism of temperature on the ballistic performance of STF-impregnated fabrics is revealed. Shear thickening fluids (STFs) can effectively enhance the impact resistance of woven fabrics, and they have excellent prospects for application in soft-wall containment casings for aero-engines. Considering that the operating temperatures of an engine casing are in the range −50 °C to 100 °C, this study sought to reveal the influence of this temperature range on the impact resistance of STF-impregnated Kevlar fabric and reveal its mechanisms. The results of rheological tests showed that temperature has a dramatic influence on the rheological properties of the STF examined, especially in low-temperature environments, where the viscosity of the STF is extremely large and the critical shear rate is extremely small. Picture-frame shear tests showed that the shear performance of the fabric at high and low temperatures decreases when compared with room temperature (20 °C). Ballistic impact tests were carried out using a gas-gun system at different temperatures. The ballistic limit, energy absorption, and failure morphology of the STF-impregnated fabrics were analyzed. The ballistic performance of the fabric at both high and low temperatures deteriorated when compared with that at room temperature. At temperatures of −50 °C and 100 °C, the ballistic limit velocity decreased to about 62.6% and 84.2% of its value at 20 °C, respectively.