Prediction And Analysis Of Mechanical Properties Of Carbon Fiber Reinforced Composite Laminates

Facing the problem of resource shortage and environmental protection,energy saving and emission reduction of traditional fuel vehicle and the development of new energy vehicles have become the main trends of the automotive industry.These two main development trends are commonly facing the problem of light weight of vehicles.As a lightweight material,composite material has been applied to the lightweight design of automobile for its advantages of high strength,high design freedom and good formability.Composite laminates with multiple layers and multiple sequence layers will be used in the design of automobile structures.It is necessary to make material performance test for all kinds of ply laminates to obtain its basic mechanical properties,which brings great inconvenience to the performance analysis of the whole vehicle structure.In this paper,the basic mechanics theory of composite materials is first expounded,and the damage forms,damage analysis and failure criteria of composite materials are discussed.Then,a large number of experiments were carried out to obtain the basic mechanical properties of carbon fiber reinforced composite unidirectional laminates,including elastic modulus and strength.Based on these experimental data,the law of variation between layers and material properties is studied.The relationship between the number of layers and the properties of materials is fitted by choosing the appropriate equation.The dispersive analysis of experimental data on longitudinal tensile strength and compressive strength is also made.The mesoscopic finite element model of composite laminates is established by using the progressive damage material model and the continuous damage material model,and the results are discussed.Finally,the fitted formula is applied to the numerical simulation of composite materials.Through analyzing the experimental data,it is found that the longitudinal tensile strength and longitudinal compressive strength data obey three parameter Weibull distribution.With the change of the number of layers,the different elastic modulus of the composite laminates basically remained unchanged,and the different strength properties changed obviously with the change of the number of layers.The empirical formula between the number of layers and the strength properties of materials is established by using the two order polynomial function.The two degree polynomial function can not only meet the requirements of small errors,butalso fit the actual experimental data reasonably.The progressive damage model can better simulate the brittle fracture process of carbon fiber reinforced resin matrix composite laminates,the curve characteristics of the force and displacement curves obtained by the reduction experiment and the key parameters of the curve.The strength predicted by empirical formula is applied to the finite element model of composite materials,and there is little error in the force and displacement of the standard experiment.