Research On Characterization Method Of Impact Damage Of Carbon Fiber Composite Laminate

Carbon fiber composite materials are widely used in the field of high-precision scientific research equipment manufacturing and other machinery manufacturing industries because of their high specific strength,high specific stiffness,corrosion resistance,pressure resistance,high temperature resistance and light weight.However,during the production and service process of carbon fiber composite materials,due to long-term operation in harsh environments,such as withstanding external impact,fatigue,creep and other environmental factors,it may cause serious and invisible internal mechanical damage to it,The overall mechanical properties and service life of carbon fiber composite materials have dropped sharply,which has seriously affected the usability and reliability of the materials.Therefore,it is very important to develop effective techniques for the prediction of the internal damage mechanism and mechanical properties of carbon fiber composite materials,and methods for detection and reliability evaluation.In this paper,T700 epoxy resin-based carbon fiber composite laminates are used as the research object.The selected specimens are successively subjected to low-speed multiple impact experiments at different energies and bending experiments of the specimens after being impacted.The experimental process uses acoustic emission detection Technology and nonlinear ultrasonic detection technology,combined with electron microscope scanning technology to observe the impact test,analyze the change trend of the nonlinear coefficient of the specimen during the impact damage of the epoxy resin-based carbon fiber composite material with the number of impacts,and then determine the carbon fiber composite Correlation between the non-linear coefficient and the number of impacts after multiple low-speed impacts of material laminates;after the impact experiment is completed,the bending test of laminates with different degrees of impact damage is further carried out.Acoustic emission technology is used to monitor the whole process of the experiment.The established model recognition method based on SVM support vector machine compares and analyzes the changes of the acoustic emission signal of each specimen during bending damage,and integrates the nonlinear coefficients of multiple low-speed impact experiments of the carbon fiber composite laminate specimen and the acoustic emission data analysis of the impacted specimen As a result,the effects of multiple low-speed impacts on the performance of epoxy resin-based carbon fiber composite laminates were obtained?...