Experimental Research And Optimization Of Flexural Properties Of Carbon Fiber Reinforced Plastic Foam Aluminum Sandwich Structure

With the development of electric vehicles,the automotive lightweight research is becoming more and more important.The carbon fiber composite foam aluminum sandwich structure is widely used in the mechanical parts of automobile and the structure of energy absorption parts,because of its light and extreme load capacity.In order to study the influence of the density of aluminum foam core layer and the different core structure on the flexural properties of the carbon fiber foam aluminum sandwich structure,this paper carried out a quasi static three point bending test on the sandwich structure of two density foam aluminum cores and three different sections of the foam aluminum core.The basic mechanical properties and failure modes under quasi static three point bending load are experimentally analyzed,theoretically calculated and numerically simulated.Firstly,the structure of aluminum foam and its sandwich structure are briefly summarized from the preparation process and mechanical properties of the sandwich structure,and the main research content and research significance of this paper are also introduced.In this paper,the structure of carbon fiber foam aluminum sandwich is made up of carbon fiber composite panel and foam aluminum core.The tensile mechanics test of carbon fiber composite panel is carried out.The tensile mechanical properties are obtained,and the compression test of aluminum foam is carried out.The basic mechanical properties of the foam aluminum compression are obtained.Secondly,three point bending experiments on the structure of carbon fiber composite foam aluminum sandwich are carried out.The deformation and failure mode of the structure of the carbon fiber composite foam aluminum sandwich structure in the three point bending experiment are observed and recorded.The ultimate load of the foam aluminum sandwich structure with different density of aluminum foam and different section shape of aluminum foam is analyzed.And the effect of energy absorption.On the basis of experiment,the bending mechanical properties of carbon fiber composite foam aluminum sandwich structure under three point bending load are analyzed.According to the theoretical calculation formula in the literature,the bending stiffness and bending strength of the carbon fiber composite foam aluminum sandwich structure are theoretically analyzed and calculated.Then the experimental data of the three point bending of the sandwich structure are compared.The results show that the experimental value of the flexural rigidity of the sandwich structure is about 10% higher than that of the rational theory,and the error is acceptable.The experimental value of the limit load of the sandwich structure is lower than that of the theoretical value.The cause of the error is analyzed and given in this paper.The failure mode of the sandwich structure under three point bending load is predicted by the theoretical formula.The results show that the theoretical prediction results are basically the same as the failure modes of the sandwich structure obtained by the experimental process.In addition,the loading process of the sandwich structure under the action of three point bending load is simulated and the results are simulated.It is in agreement with the experimental curve,and the failure mechanism of the bonding interface is in good agreement,and the limit load error is 3%.The correctness of the finite element model and the material model of the carbon fiber composite foam aluminum sandwich structure is verified.Finally,the optimization design of CFRP aluminum foam sandwich mechanism with the maximum energy absorption and the lightest weight is carried out.According to the design requirements,the objective function of multi-objective optimization of sandwich structure is determined,and the influence of the changes of structural parameters on the energy absorption and quality of the sandwich structure is analyzed.The design variables are screened out and the multi-objective optimization problem of the sandwich structure is completed.Through the Latin square test,the sample points are collected in the design variable interval,and the response values are calculated.The approximate mathematical model of the optimized target is constructed by using the Kriging agent model.Finally,multi-objective genetic algorithm NSGA-II is used to solve the multi-objective optimization problem,and the final optimization scheme is given,and the optimization results are verified.Compared with the sandwich structure before optimization,the optimized sandwich structure can improve the energy absorption performance and achieve the goal of reducing the quality of sandwich structure.