A Study On The Mechanical Properties Of Glass Fiber/Epoxy Resin Composite

Glass fiber/epoxy resin(GF/EP)composite materials are widely used in various fields due to their excellent properties,such as mechanical manufacturing,electronic packaging,aerospace et al.However,with the continuous progress of the society,the requirements for GF/EP composite materials are also continuously higher.In order to further improve the mechanical properties of GF/EP composite materials,it is necessary to fully understand the mechanical properties of GF/EP composites.The present work studied the static and dynamic loading conditions and the mechanical properties of micro/nano scales,and investigate the constitutive relationship under the condition of quasi static and dynamic load.The experiment material are 55 wt.%,75 wt.% and 95 wt.% of GF/EP specimens.Quasi-static uniaxial tension-compression tests were performed on GF/EP materials at different temperatures(in the range of 50°C to 110°C),and uniaxial tension-compression tests under quasi-static conditions at room temperature were used as controls.The quasi-static mechanical properties of GF/EP materials at room temperature and the influence of temperature on the quasi-static mechanical properties of GF/EP materials were studied.The experimental results show that the elastic modulus and yield strength of the specimen decrease with increasing temperature.The quasi-static compressive stress-strain curve of GF/EP specimen at room temperature is fitted using the ZWT viscoelastic constitutive model.The combined results are ideal.The ZWT model can describe the constitutive behavior of GF/EP specimens.Dynamic compression experiments of GF/EP under different strain rate of stress-strain relationship were obtained,showing the behavior of highly nonlinear material.The GF/EP showed strain rate sensitivity when strain rate is higher than a certain critical value.GF content of 75 wt.% of specimen are brittle deformation in the test,specimens with GF content of 95 wt.% show a brittle deformation and the plastic deformation,indicating that the increase of GF will increase the toughness of the material.Using ZWT viscoelastic constitutive model to fit the stress-strain curve of the glass GF/EP specimen under different strain rates,the fitting results are ideal,and the ZWT model can describe the constitutive behavior of GF/EP specimen.Nanoindentation experiments of GF in different kinds of epoxy resin(EP)on the micro/nano mechanics were conducted.The different GF content for the influence of epoxy resin on mechanics performance was investigated.As GF content increased,the EP's carrying capacity,maximum pressure into the depth of the load is bigger.In addition,with the increasing of GF content,loading time required to achieve the same pressure depth extension.Based on continuous stiffness method,GF strengthen EP materials elastic modulus and the hardness increases with the increase of GF content.The elastic resistance of high fiber content EP and local pressure resistance are better.The creep behavior of the composite material is similar to that of uniaxial tensile.