Influence Of Z-yarn For The Multilayer Fabric Composite Interlayer Dissection Behavior

Due to their light weight and high strength properties textile composites are widely used in the fields of aeronautics and marine engineering.As people’s awareness of environmental protection and non-renewable energy consumption,making lightweight and low fuel consumption has become an important indicator of industrial design.More and more car companies are investing in the research and application of textile composites to replace the related metal sheet metal structures in automobiles.Therefore,certain cross-sectional structures of the textile composite materials have been proposed,such as composite pipe,T-beam,U-groove.However,the fabric reinforcement structure of textile composites is an important factor that affects the mechanical properties of the composites.Therefore,a large amount of fabric reinforcements are woven and weaved.Among the common woven fabric reinforcements are unidirectional fabrics,plain weaves and three-dimensional orthogonal fabrics.This composite has the significant advantages of high damage tolerance,approximate molding and high production efficiency.Reinforcing the fabric structure has a direct effect on the mechanical properties of the composite member under different loading conditions.In this paper,the mechanical properties of three different fabric-reinforced composite structures with a semi-hexagonal cross-section structure were studied experimentally and simulatively.Three different fabric structures are one-dimensional unidirectional fabric,two-dimensional plain weave fabric and three-dimensional orthogonal fabric.The three kinds of fabric reinforcements were made of resin,and the fabric-resin composite with half-hexagonal cross-section structure was prepared by vacuum mold-assisted molding.This half-hexagon structure is widely used in the automotive field.Its axial compressive properties are very important in industrial applications.Therefore,this paper mainly through experimental and finite element simulation study of the semi-hexagonal composite structure of the axial compression properties and analysis of the three composite materials in the quasi-static axial compressive load Fabric structure on the destruction of the specific content of this article will start from the following aspects:Chapter 2 mainly states the preparation process of the sample of the half-hexagonal fabric composite structural member.First of all,the application of semi-hexagonal structural parts and the relevant cross-sectional dimension design are described in detail.Metal molds for forming composite materials are designed according to the cross-sectional dimensions.Then we focus on the weaving process and structural features of three different fabric reinforcements.Finally,a detailed description of the vacuum mold assisted molding technology to prepare the overall process of fabric composites.Chapter 3 Full scale finite element modeling and destructive description of experimental specimens.First,by assuming the model,we simplify the establishment of yarn units and resin units with unique trajectories according to the assumptions.In the end,the initial and development of failure are simulated by using the criterion of flexible failure and shear failure combined with the unit properties established in this paper.In Chapter 4,axial compression experiments were conducted on three different fabric composites.Details of the experimental process and the recorded data.Then,the results of the experiment are analyzed emphatically.The three kinds of fabric composites show three different failure modes under the axial crushing,which are step by step delamination,total deforming and folding collapse,and mixing failure respectively.By comparing the experimental data,it is found that the multi-layer unidirectional fabric composite has the lowest peak force under axial load but the best energy absorption.However,the three-dimensional orthogonal fabric composite has the highest peak force,but its energy absorption performance is the worst.Chapter 5 analyzes the failure characteristics of the three kinds of fabric composite structures based on the simulation results and the experimental results.The comparison between the force-displacement curves in the simulation results and the force-displacement curves in the experimental results shows that the reliability of the simulation results is improved by homogeneous half Simulation and Analysis of Hexagonal Structure Particulars Stress distribution and failure mode of semi-hexagonal structure under axial compression.Then according to the stress distribution on the yarn in the simulation result and the internal failure phenomenon in the simulation results,the structural features of the fabric reinforcement result in different internal forces of the composite material,so that different failure modes and different mechanical properties are obtained.The sixth chapter summarizes the work of this paper and prospects the follow-up research.