Research On Impact Insulation Of Textiles Under Low Velocity Impact Based On Viscoelastic Theory

In modern society,damages caused by low velocity impact(?25m/s)are significantly growing.In the engineering field,using viscoelastic material for impact protection is considered as a practical and effective method.Knitted spacer fabric is used as a protective buffer layer.This paper focuses on how viscoelasticity of these fabrics affect impact insulation under low velocity impact.And based on research result,low velocity impact protection structure has been improved.This research has important significance for guiding the construction of protective structure.Based on viscoelastic theory,simple real elastic and viscous models was designed and built.In order to explore how elasticity or viscosity affects impact insulation,the two models were subjected to low impact loads.YG026D multifunctional electronic fabric strength machine was used to test elasticity of warp spacer fabrics.Elasticity was characterized with compression modulus.According to vibration transmission characteristics testing method,the viscosity testing device was built.Viscosity was characterized by damping ratio.Various warp-knitted spacer fabrics were tested by the means.Performance of impact insulation was measured by self-developed low-velocity tester.How viscoelasticity of cushion materials affect low velocity impact insulation was analyzed.In the end of the paper,a comparison test of anti-impact performance between pure glass fibers reinforced laminate panels and self-made sandwich panels.The warp-knitted spacer fabrics were used as buffer layers and combined with sandwich panel in protective structure.Then they were taken to conduct low velocity impact test.According to impact results of combined structures,an improved method to improve anti-impact effectiveness of low velocity impact protective structure was proposed.It was found that the greater elasticity,the impact time is longer and the remaining load is higher.Viscous factor is in contrast.Elasticity and viscosity of warp-knitted spacer fabric were characterized.And the fabrics were subjected to low impact loads.When viscoelastic material such as warp-knitted spacer fabric is subjected to impact,elasticity and viscosity affect impact insulation by a means of mutual influence and constraint.For low velocity impact protective structures,damping/compression modulus ratio(viscoelastic ratio)was proposed.Compared impact results between pure glass fibers reinforced laminate panels and self-made sandwich panels,it is found that the impact insulation of protective structure can be improved by adding the damping layer to panel.The warp-knitted spacer fabrics were used as buffer layer and combined with sandwich panel in protective structure.According to the impact results of the combinations,it is found that viscous fabric as cushion layer can improve the impact insulation performance of structure.Within this study,it is found that when the viscoelastic ratio is around 4.08,warp-knitted spacer fabric combined with sandwich panel of woolen fabric core has the best performance of impact insulation.