Preparation And Impact Resistance Of Shear Thickening Fluid Reinforced Composites

Synthetic fiber products have been widely used in all aspects of industrial and agricultural production and life,and play an important role in promoting the development of modern society.However,the fiber cloth is easily pierced by some sharp articles,and the fiber sheet is prone to breakage,delamination,etc.when subjected to high energy impact,and the use of the fiber product is limited to some extent.Shear thickening fluid(STF)as a special fluid,its viscosity will increase with the increase of shear rate.If it is added to fiber cloth and fiberboard,it is expected to improve the resistance of fiber products.Impact performance.In this thesis,the preparation process of STF and STF-fiber cloth and STF-fiberboard composites were studied.The microstructure of these composites was studied by scanning electron microscopy,stereo microscope,advanced rotational rheometer and Fourier transform infrared spectroscopy.Impact resistance and puncture resistance.The main findings are as follows:(1)It was found that the silica mass fraction has an important influence on the shear resistance of STF.As the mass fraction of silica increases,the viscosity of the STF increases correspondingly,thereby improving the shear resistance of the STF.Shear thickening is divided into four stages,namely: shear instability,shear thinning,shear thickening,shear thinning again.(2)STF-reinforced fiber cloth composites have excellent impact resistance.It was found that the addition of STF improved the impact resistance of glass fiber cloth,carbon fiber cloth and Kevlar fiber cloth under low speed single layer conditions.Under low-speed double-layer conditions,STF-bonded carbon fiber cloth and Kevlar fiber cloth composites have better impact resistance than STF-filled glass fiber cloth composites and can withstand 3.13 m/s impact.The four-layer STF-Kevlar fiber composite can withstand 173 m/s under high-speed impact.(3)STF and coupling agent significantly enhance the ballistic impact resistance of fiberboard composites.It was found that the addition of STF or coupling agent to the ballistic impact resistance of fiberboard composites has certain influence,but theaddition of STF and coupling agent can greatly improve the ballistic impact resistance of fiberboard composites.For the 5-layer fiberboard composite,the addition of STF and coupling agent reduces the damage depth of the glass fiber board,carbon fiber board and Kevlar fiber board,improves the ballistic impact resistance,and can withstand the impact of 5 J.