Buckling And Post-buckling Analysis Of Glass/Carbon Fiber Hybrid Composite Laminate Structures

Glass/carbon fiber hybrid composites are made of glass fiber and carbon fiber Stiffened with the same resin matrix,which combines the advantages of both fibers and can achieve the synergy of strength,stiffness and toughness of both,with good comprehensive mechanical properties,better design than the traditional single fiber composites,and have been widely used in various fields such as aviation and aerospace.However,for the glass/carbon fiber hybrid composite laminate structure,it will be subjected to compression load in the process of practical application,and the common failure form is buckling,and there is usually a large post-buckling load capacity after the buckling of the structure.Therefore,it is of great engineering significance to improve the efficiency and load-bearing capacity of glass/carbon fiber hybrid composite laminate structures under the premise of ensuring the safety of laminate structures.In this paper,Buckling and post Buckling studies on the glass/carbon fiber hybrid composite laminate structure are carried out,and the specific research contents and conclusions are as follows.(1)The numerical analysis model of the glass/carbon fiber hybrid composite laminate was established in the finite element analysis software,and the eigenvalue buckling analysis was carried out,and the effects of different temperatures,fiber lay-up angles,lay-up methods,boundary conditions,mixing ratios and other factors on the critical buckling load of the structure were studied,and compared with the calculated analytical solution in matlab and literature solutions to verify the reliability and The validity of the model is verified.It is found that with the increase of temperature,the Buckling load of the structure decreases continuously;the structural Buckling load shows a decreasing trend with the increasing angle of fiber lay-up,and the Buckling load of the structure is the largest when the unidirectional lay-up angle is 0°;the structural Buckling load will show a decreasing trend as the carbon fiber monolayer gradually moves from the outer layer to the middle layer;with the increase of the solid support edge in the boundary conditions,the Buckling The Buckling load tends to rise with the increase of solid support edge in the boundary conditions;the highest material utilization is achieved when the C:G mixing ratio is 1:7 at a certain thickness and number of laminate layers;the Buckling load value is greater when the mixing method is sandwich mixing than interlaminate mixing under the same lay-up order,and the Buckling load of the structure is greatest when the carbon fiber veneer is placed in the surface layer and the glass fiber veneer is placed in the core layer.(2)In order to improve the Buckling resistance of the glass/carbon fiber hybrid composite laminate,the reinforcement strips were added on the basis of the original laminate,and a model of glass/carbon fiber hybrid composite Stiffened plate was established to carry out the eigenvalue Buckling analysis.In the process of analysis,it is found that the three types of reinforcement,T-type,J-type and I-type,can significantly improve the Buckling capacity of the glass/carbon fiber hybrid composite laminate,among which the I-type reinforcement has the highest lifting efficiency,and the Buckling load of the structure increases with the increasing number of reinforcement.The height of the bars has a greater influence on the Buckling load of the Stiffened panel structure,and the highest efficiency of the Buckling resistance of the structure is achieved when the height of the bars is 10 mm;for the laying method of the bars,increasing the number of layers laid at 0° and decreasing the number of layers laid at 90° can effectively improve the Buckling resistance of the structure.(3)Based on the above eigenvalue buckling analysis of the structure,the post buckling process and asymptotic damage of the glass/carbon fiber hybrid composite laminate and Stiffened plate are then analyzed,and the first-order buckling mode of the buckling analysis is added to the post buckling analysis process as the initial defect of the structure,and the two-dimensional Hashin criterion is introduced to establish the stiffness degradation model of the structure and track the post buckling equilibrium path.In the process of the study,it was found that both the laminate and the Stiffened plate had larger post-buckling strength after buckling,and the buckling load value of the glass/carbon fiber hybrid composite laminate with the C:G mixing ratio of 1:1 reached 92.72% of that of the single carbon fiber composite laminate and 2.37 times of that of the single glass fiber composite laminate when the lay-up method was the same.The post-buckling ultimate load capacity reached 84.6% of that of the carbon fiber composite laminate and 1.93 times that of the glass fiber composite laminate;during the analysis of the asymptotic damage of the glass/carbon fiber hybrid composite laminate and Stiffened plate,it was found that the main failure mode of the laminate was the tensile damage failure of the matrix and the compression damage failure of the fiber,and the area and trend of the damage were mainly related to the laying angle and laying sequence of the fiber.The damage areas and trends are mainly related to the laying angle and laying order of the fibers,the more serious damage areas are the surface and bottom layers,and the damage trend is along the four corners of the board to the center;the main failure modes of the Stiffened panels are the tensile damage failure of the matrix of the skin,the compression damage failure of the fibers,the tensile damage of the tendons and the tensile damage of the matrix.