Performance Simulation And Application Of Honeycomb Sandwich Structure Composite

Energy saving,safety and environmental protection have always been hot topics in the automobile industry,and automotive lightweight technology is an important way to achieve this goal,in which the use of lightweight materials is the main measure to achieve automotive lightweight.Composite honeycomb sandwich structure is widely used in aerospace,automobile,ship and many other fields because of its excellent properties such as light weight,low cost,high strength,sound insulation and shock absorption,and has become a research hotspot of lightweight materials.For the complex structure such as honeycomb sandwich structure,it is very inconvenient to establish the detailed honeycomb model,which not only needs a lot of calculation,but also consumes a lot of time and cost,so it is necessary to simplify the analysis.In this thesis,the equivalent model of composite honeycomb sandwich structure and its application in automobile floor are studied.Firstly,three commonly used equivalent theories of honeycomb sandwich structure are introduced,namely quivalent plate theory,honeycomb plate theory and sandwich panel theory.The finite element models of three equivalent theories are established with a specific example,and compared with the detailed honeycomb model.The results show that the sandwich plate theory has the highest equivalent accuracy and faster calculation speed.Secondly,the basic mechanical properties of glass fiber panel and honeycomb sandwich structure are studied,and the finite element analysis of the equivalent model is carried out based on the sandwich panel theory:(1)the tensile,compression and shear tests of the glass fiber panel are carried out,and the mechanical property parameters of the glass fiber is obtained;(2)the flat pressure test and bending test of aluminum honeycomb core and honeycomb sandwich structure are carried out to study their mechanical properties;(3)the finite element model of the glass fiber is established and compared with the basic performance test of the glass fiber face to verify the accuracy of the finite element model;(4)the flat compression finite element model of honeycomb core and the three-point bending finite element model of honeycomb sandwich structure are established and compared with the corresponding experiments.The results show that the deformation mode and the mechanical properties of the honeycomb finite element model are basically consistent with the experiments,which fully verifies the accuracy of the equivalent model of honeycomb sandwich structure.Finally,on the basis of verifying the accuracy of the equivalent model,the equivalent model of the honeycomb sandwich structure is applied to the automobile floor,and the influence of different cell parameters on the performance of honeycomb sandwich structure is studied.The honeycomb sandwich structure is used to replace the original steel plate floor to reduce the weight of the car,and the honeycomb floor structure is improved and designed.The results show that after using the honeycomb structure to replace the original steel plate floor,on the premise of meeting the original performance requirements,the weight of the automobile frame is reduced from 427.9kg to 380.3kg,and the weight is reduced by 11.1%,which fully realizes the lightweight design of the structure.Through the study of the cell parameters,it can be known that if the thickness of the cell wall/side length of the cell increases,the strength and rigidity performance of the honeycomb sandwich structure can be improved.