Study On Mechanical Properties Of Modified UHMWPE Fiber Weft-knitted Composites

Weft knitted fabric as a kind of textile reinforced composites and can endowed composites material with many advantages such as better formability,can be used to do composites of no fold,complex-shaped,better energy absorption performance.It has been widely used in safety protection and so on.UHMWPE fiber is the third generation after the carbon fiber,aramid fiber,which is the only one kind of fiber that can float on the surface of the water.It is with high strength and high modulus better weather resistance and chemical corrosion resistance.So it aroused general interest of researcher.The preparation and mechanical properties of modified UHMWPE fiber weft knitted composites were studied in this paper.The impact property of the composites was simulated using finite element soft package of ABAQUS.It can provide some experimental date and theoretical reference for the further study of composites.In order to meet the requirements of knitting yarn,the UHMWPE multiplex yarn was been deal with twistingand destaticization processing.The weft plain fabric is weaved successfully by adjusting weaving process repeatedly.The preparation of composite used the process which combines the advantages of VARTM process and molding process.Three kinds of composites of 8-layer,12-layer and 16-layer were prepared successfully.The mechanical properties of the different layer composites were tested.By the analysis of strength-displacement curve and stress-strain curve,it can found that 16-layer composite has the overall mechanical properties,flowed by 12-layer,8-layer is the worst.Due to the asynchrony of destruction of different layers,the tensile strength,compression strength decrease with the increase of the layer number.When the strain is small,the damage occurs to resin matrix,while reinforced structure just has deformation.The damage form of the sample was observed by SEM.It been found that the resin coated on the surface of the barefibers.And fiber pull was not appeared.This indicated that after modification,the cohesive action between fiber and resin was increased.A kind of method to establish weft plain fabric three-dimensional model,which combines the characteristics of Pierce model,B-spline and the weft plain fabric's three-dimensional shape.Then using the finite element simulation software ABAQUS to do the simulation research of 12-layer weft plain knitted composites.Compare the simulation results with the test results,the damage form and energy value of impact sample is close to the test results,which does mattingthe further study of the mechanical properties of the composites.