经编间隔织物增强柔性复合材料冲击性能

Impact properties of warp knitted spacer fabric reinforced flexible composites

针对传统个体防护材料刚硬、限制人体活动的缺点,设计了2种柔性复合材料:剪切增稠液(STF)和硅橡胶填充经编间隔织物(WKSF)柔性复合材料,并对其冲击性能进行研究。WKSF具有上、下两个表层和间隔丝构成的间隔层,在其间隔层中加入STF和硅橡胶2种柔性材料。STF采用将纳米SiO2分散于聚乙二醇(PEG)中制成,硅橡胶采用硅胶和固化剂混合而成。采用流变仪对STF的流变性能进行测试,采用Instron落锤冲击仪对WKSF及其复合材料的冲击性能进行测试。实验表明:STF在达到临界剪切速率后出现剪切增稠现象,纯织物的冲击过程可分为弹性、平台和压实3个阶段,且具有明显的平台阶段;经填充后所制成的2种复合材料的冲击过程与纯织物明显不同,其载荷-位移曲线呈线性;加入硅橡胶的复合材料刚度较大,没有应变率效应;加入STF的复合材料具有较好的能量吸收性能和明显的应变率效应。

According to the problem of rigid and restricted physical activity of the personnel protection material,two kinds of flexible composites with shear thickening fluid(STF)and silicon rubber filling warp knitted spacer fabric(WKSF)were designed,and the impact properties of composites were studied.The WKSF has the upper and lower outer layers and spacer layer,the spacer layer was composed of spacer yarns.STF and the silicon rubber were filled into the spacer layer.STF was composed of nano-SiO2 suspended in polyethylene glycol(PEG)liquid,and silicon rubber was composed of silicone component and curing agent mixture components.The rheometrics was used to test the rheological behaviors of STF,and Instron drop tower impact tester was used to test the impact properties of the WKSF and the flexible composites.Results indicate that STF shows shear thickening transition after reaching the critical shear rate.The impact process of the pure fabric can be divided into three stages of elastic stage,plateau stage and densification stage.There is a plateau stage for the WKSF.The impact processes of the two kinds of flexible composites are different from pure fabric,the force-displacement curves are in linear way.The silicon rubber filled composites show higher stiffness and no strain rate effect.The STF filled composites show higher energy absorption capacity and obvious strain rate effect.