Research On The Interface And Mechanical Properties Of Aramid-UHMWPE Weft-jersey Hybrid Composites

The development trend of industry is to use high-performance fiber to manufacture lightweight and high-strength composites.The weft plain knitted fabric should have a special coil structure to make the composite have good impact resistance.Aramid fibers are widely used in aerospace,automobile and protective materials due to their excellent mechanical properties.Ultra-high molecular weight polyethylene fiber(UHMWPE),as the fiber with the lowest relative density,the highest specific strength and specific modulus among high-performance fibers,which is of great significance to the lightweight development of automotive materials.The interface properties of composite play an important role in their mechanical properties.The interface between the fiber and resin is one of the most important factors affecting its mechanical properties.The purpose of this study is to increase the interfacial properties between the fiber and resin by surface modification of fibers,so as to improve the comprehensive properties of composite.Without compromising the mechanical properties of the highperformance fibers themselves,hybrid composites for automobiles with better mechanical properties have been developed.For the surface modification of fibers,a sol-gel method is used to prepare coating sol to modify the coating of aramid fiber,UHMWPE fiber and its weft plain knitted fabric.The morphology changes were analyzed by scanning electron microscope,and FTIR and XPS analysis were performed to determine the coating material.Through the friction coefficient test,contact angle analysis and interface shear strength test,it is proved that the sol-gel treatment is an effective way to improve the interfacial properties between the fiber and resin,and has no effect on the tensile properties of the fiber itself.The interfacial shear strength of aramid fiber increased by 38.26%,and that of UHMWPE fiber increased by 50.97%.According to the hybrid ratio,ten kinds of aramid-UHMWPE weft plain knitted composites with different hybrid structures were designed,and the mechanical properties of the hybrid composites were explored.The results show that the tensile strength of the interlayer hybrid composite increases with the increase of the UHMWPE fabric layer content.Under the same hybrid ratio,the composite has better tensile properties when the UHMWPE sandwiches the aramid.When K:U=1:3 with aramid fabric as impact surface,the impact resistance of hybrid composites is the best.When K:U=3:1 with UHMWPE fabric as impact surface,the impact resistance of hybrid composites is the best.All hybrid methods show positive hybrid effects,and hybrid composites with different hybrid ratios and layup methods should be selected according to their actual use.Finally,this paper uses the 3D modeling software Rhinoceros to establish the physical model of weft plain knitted fabric,and uses abacus finite element simulation to analyze the impact resistance of weft plain knitted composites.The simulated values were compared with the experimental values and the results were in good agreement with the experimentally obtained load-time curves.