剪切增稠液改性软织物的SHPB冲击测试研究

以SiO2为分散相、乙二醇为分散剂制备剪切增稠液来浸渍芳纶纤维Kevlar 49平纹织物,开展了对坯布与浸渍布的霍普金森杆(SHPB)低速冲击实验。使用多频投影条纹反相补偿法对织物背面胶泥冲击坑进行三维形貌光学测量,结果显示胶泥冲击坑形貌近似为“菱形”,且剪切增稠液浸渍布的胶泥冲击坑的变形跨度比明显小于坯布。通过建立胶泥冲击坑体积与织物变形能之间的标定关系,提出了能量吸收率指标来评价柔性织物的抗冲击性能。实验显示能量吸收率随冲击气压增加而升高,且浸渍布的能量吸收率明显高于坯布,这是剪切增稠液增大纱线摩擦和限制纱线滑移所导致的。

SHPB impact test of shear thickening liquid modified soft fabric

The shear thickening liquid(STF)is prepared by using SiO2as the dispersed phase and ethylene glycol(EG)as the dispersing agent to impregnate Kevlar 49plain fabric,and low-speed impact test for the neat fabric and the impregnated fabric is conducted by the split Hopkinson pressure bar(SHPB).The multi-frequency inverse-phase fringe projection profilometry is used to measure the 3Dshape of clay impact basin.The experimental results show that the“diamond shape”occurs in the impact basin and the deformation span ratio of STF impregnated fabric is obviously smaller than that of neat fabric.By establishing the calibration relationship between the volume of impact basin and the fabric deformation energy,the energy absorption index is proposed to evaluate the impact resistance of flexible fabrics.The experimental results show that the energy absorption index increases with the impact pressure,and the energy absorption rate of STF impregnated fabric is obviously higher than that of neat fabric,which is caused by the increase of yarn friction and the limitation of yarn slip caused by the shear thickening effect of STF.