Research On The Mechanism Of Yarn Movement And Material Puncture Of Fabric Composite Membranes

In actual use,the slippage of yarn in the fabric(the relative slippage of the yarn that constitutes the fabric)is an important deformation or failure mode,which can significantly change the energy absorption capacity and yarn density of the fabric,and may cause the yarn from The loosening of the fabric causes a change in the fabric weave configuration and plays an important role in the in-plane mechanical response of the fabric composite material.In addition,in practical engineering applications,puncture damage(such as projectile puncture,accidental puncture of membrane building membrane surface punctures,wind-induced debris puncture,etc.)and tear propagation after puncture are common failure modes of membrane materials,and Yarn movement is a basic phenomenon in many forms of destruction.Mastering the yarn movement mechanism and response has important guiding significance for improving the puncture resistance and tear resistance of the membrane.Therefore,it is very important to study the mechanical properties of yarn movement.Penetration damage is a common type of failure in membrane structure engineering,such as accidental puncture of membrane building membrane surface,wind-induced debris puncture,etc.In special use environments,high-speed puncture damage,such as projectile puncture damage,is also involved.Mastering the mechanical properties and failure mechanism of flexible membrane puncturing is very important for the assessment of the safety damage of the membrane and improving the puncture resistance of the membrane,so as to reduce the probability of puncturing the fabric material.As the mainstream new material of the outer membrane of modern inflatable membrane structure,warp-knitted composite membrane material has gradually attracted the attention of the scientific community.At present,there are few studies on its mechanical properties and mainly focus on the in-plane mechanical properties.There is a lack of research on the out-of-plane puncture mechanism.Mastering the mechanical properties and destruction mechanism of warp-knitted membrane materials to improve the puncture resistance of the membrane materials The rupture performance,reducing the probability of accidental puncture and the assessment of the safety damage of large-span inflatable membrane buildings are very important.This paper takes the mechanical properties of membrane materials as the research background,uses plain woven fabrics and warp knitted membranes as the research objects,and uses the finite element numerical analysis method to investigate the yarn movement mechanism and puncture response mechanism of plain weave fabrics,and explores the warp woven The puncture mechanical properties of the film material and the tear failure characteristics after puncture.The main contents include the study on the mechanical properties of yarn movement of plain weave fabric,the mechanical properties of plain fabric puncture,and the mechanical properties of warp knitted fabric membrane puncture.First,this paper uses ABAQUS finite element software to simulate the movement process of plain weave yarn,systematically analyzes the influence of friction coefficient,model size,pretension and yarn movement rate on yarn movement response,and deeply studies the drawn yarn The coupling relationship between the breaking length and the drawing breaking strength and the friction coefficient between the yarns and the pre-tension of the base fabric,it is proposed that stress homogenization is an important factor influencing the increase of the yarn drawing length.Secondly,using the method of finite element software simulation analysis to simulate the puncture process of flexible woven materials,the damage characteristics of plain weave fabrics under high-speed impact of the elastic body were explored.The puncture response mechanism,as well as the puncture failure response of the film material under the action of low-speed sharp objects and wind-wrapped debris,realizes the meso-level exploration of the stress-strain distribution,deformation characteristics and puncture performance of the woven fabric during the puncture process.The conclusions obtained provide an effective prediction method for the design of anti-puncture fabrics,and can also be extended to the analysis of anti-puncture of other structural materials.Finally,taking the typical warp-knitted membrane Seaman PVDF8028 as the research object,the uniaxial tensile test and the membrane electron microscope scanning test were carried out to obtain the main mechanical properties and geometric parameters of the membrane.Then,based on the finite element method,the two-way limited Through the simulation of warp knitted membrane puncture,systematically investigate the influence of the horizontal angle of puncture,the size of the burr,the position of puncture and the puncture angle on the puncture performance of the membrane,and analyze the mechanical properties of the warp-knitted membrane at a micro level And,based on the fracture form of the film material after the puncture of the sheet-shaped puncture tool,the tear propagation under the bidirectional equal stress ratio was studied.The tear propagation is mainly based on the fracture form of the rupture fracture of20 mm and 30 mm.The simulation of tear propagation at the horizontal rotation angles of thorns(0 °,45 °,90 °)explores the morphology of the tear propagation of the woven membrane after puncture.The conclusions obtained can provide a useful reference for the design and safety analysis of related membrane structures.