Research On The Performance Of Adhesive CFRP Corrugated Plate Under Three Point Bending And Hygrothermal Ageing

In order to meet the social demand of energy saving and emission reduction,automobile lightweight has been concerned as an effective alternative measure,which is of great significance to the sustainable development of automobile industry.Corrugated plate structure is a typical lightweight structure with thin wall and light weight.At present,it is can be used in architecture,and can also be used as a load-bearing and energy absorption structure in front longitudinal beam of chassis and Y-beam of body.In this paper,the CFRP(carbon fiber reinforced composite)with light weight and high specific strength is used to replace aluminum alloy to make corrugated plate core plate,and the CFRP aluminum alloy corrugated plate structure is obtained.At the same time,the adhesive joint is used to replace the traditional connection method to further improve the lightweight degree of the structure.The influence of the thickness of the rubber layer on the mechanical property,energy absorption and the failure process of the rubber layer was studied by three-point bending test.Through this test,the mechanical properties and energy absorption of three corrugated sheet structures with different thickness and corrugated sheet structures with different core are compared and analyzed.In addition,considering the complex application environment of corrugated plate structure,the aging behavior of epoxy resin adhesive layer and CFRP core plate was studied.In this paper,the process of hygroscopic weight gain of CFRP in high temperature and high humidity environment is recorded.The basic mechanical properties of CFRP before and after saturated hygroscopicity were measured and compared.Then,based on ABAQUS software,the cohesion model and Hashin model was used to simulate the three-point bending test of corrugated plate structure for adhesive layers and CFRP Core board,and the simulation results were in good agreement with the experimental results in terms of load displacement curve and structural failure appearance.According to the consistent results of experiment and simulation,the bearing capacity and failure appearance of glue-bonded CFRP aluminum corrugated sandwich structures with different thickness are obviously different.Compared with 0.5mm and 1.0mm,the sandwich structure with 0.2mm adhesive thickness has the most superior mechanical properties and stability.In terms of Hygrothermal aging,the Fickian water diffusion model was used to simulate the damp-heat aging process of adhesive layer and CFRP core plate.The simulation results show that the relative area of CFRP in contact with the external environment is much larger than that of the epoxy resin adhesive layer due to the structural design.The time for CFRP core plate to reach water absorption saturation is only 45 days,while the time for the adhesive layer to reach waterabsorption saturation is 960 days,it also proves the necessity and practical value of the research on the phenomenon of CFRP hygrothermal aging and performance degradation after aging.