Study On The Influence Of Interface Performance On Energy Absorption Of Flexible Protective Structure

UHMWPE fiber is the third generation of high-strength,high-elasticity,high-performance fiber after carbon fiber and aramid fiber.The UHMWPE plain-woven fabric has been widely used in lightweight flexible impact protection systems.It is a hot research topic in recent years to better to design lighter and more effective impact protection structures.There are many factors that affect the impact energy absorption of high-strength fabric structures.The interfacial properties such as friction between the yarn and yarn,the projectile and the fabric are important factors that determine the ability of the fabric structure to absorb impact energy.In order to explore the influence of interface performance on the energy absorption effect of plain-woven fabrics,and to design a high-level flexible protective structure,the following work was carried out in this paper:(1)The tensile test of UHMWPE and Kevlar yarns is carried out on the MTS material testing machine to obtain the initial elastic modulus,failure stress and failure strain of single bundle of UHMWPE and Kevlar yarns.The UHMWPE and Kevlar plain-woven fabric pull-out test is carried out on and obtain the friction coefficient between the Kevlar yarns indirectly,the friction coefficient value is between 0.05-0.08.During the pull-out test of plain-woven fabrics,no matter what kind of yarn,the greater the pull rate makes the limit load of the yarn pull-out force bigger.(2)Based on the microscopic morphology of the yarn,a mesoscopic model of plain-woven fabric is established.Use ABAQUS finite element analysis software to establish a finite element model of the yarn layer.The orthotropic material model is used to define the material constitutive relationship and the maximum tension stress criterion defines the failure of the yarn.The simulation results are compared with the test results to verify the accuracy of the high-speed impact simulation of the plain-woven fabric.(3)The numerical simulation of impacting UHMWPE plain-woven fabric under different interface properties shows that friction loss energy is not the main energy absorption mechanism,and yarn kinetic energy and yarn strain energy are the main energy absorption mechanisms.When the projectile impacts the pure UHMWPE plain-woven fabric,the friction between the yarn and the yarn increases the energy absorption of the fabric.However,when the friction between the yarn and the yarn exceeds 0.1,the energy absorption capacity of the fabric is weakened,that is,there is a critical value of the interface friction.When impacting viscous UHMWPE plain-woven fabrics,there is no critical value for yarn-to-yarn friction.It is presumed that the viscosity between yarns is equivalent to the friction between yarns.Viscous plain-woven fabrics are equivalent to applying yarns greater friction between the yarns at the initial stage.(4)The numerical simulation of impact braid plain-woven fabric and Kevlar plain-woven fabric under different interface properties is carried out.The results show that the energy absorption effect of plain-woven fabrics woven by fibers of different materials is quite different.In the case of friction between the same projectile-to-fabric and yarn-to-yarn,the energy absorption effect of Kevlar plain-woven fabric is 42%-54% of the energy absorption effect of UHMWPE plain-woven fabric,and the energy absorption effect of braid plain-woven fabric is 53%-63% of that of UHMWPE plain-woven fabric.(5)The numerical simulation analysis of the single-layer plain-woven fabric reinforced H-section steel is carried out to explore the protective effect of the plain-woven fabric reinforced H-section steel to provide the reference for engineering application.The research in this paper provides analysis methods for the application of UHMWPE plain-woven fabrics in lightweight flexible protective structures,and provides useful reference and technical reserves for further research or development of UHMWPE protective structures,with a view to having a wide range of applications in key parts of field fortification and protective projects.