Structural Mechanics Analysis And Finite Element Simulation Of PP Glass Fiber Composite Honeycomb Sandwich Core

Automotive lightweight technology is the intersection and integration of advancedtechnologies such as new lightweight materials,lightweight structures,and lightweight manufacturing.With the development of materials and advances in technology,the search for lightweight materials is one of the important measures adopted by the current automotive light-weighting.The composite honeycomb sandwich structure has gradually become a hot spot in the research of automotive lightweight materials due to its low density,high specific strength,high corrosion resistance,and high insulation properties.However,when the honeycomb sandwich structure is applied in a large area,its geometric modeling and finite element simulation are very tedious and inefficient,which greatly limits the wide application of the composite honeycomb sandwich structure in automobile bodies.In order to solve this problem,this paper combines the homogenization theory and finite element simulation to propose a macroscopic equivalent model of the honeycomb sandwich and complete the transformation from the cellular microstructure to the macroscopic model,which greatly improves the finite element simulation efficiency of the honeycomb sandwich structure and shortens research period.In this paper,the close-packed cylindrical polypropylene honeycomb is chosen as the sandwich's core,and the continuous glass fiber reinforced polypropylene laminate is chosen as a sandwich's skin.And in this paper,the mechanical properties of sandwich sandwich structure and finite element simulation are studied in depth.Firstly,for the honeycomb core in the sandwich structure,a finite element model of cellular core compression was established with the finite element simulation software Hyper Mesh and calculate by Ls-Dyna.The compressive performance of this finite element model is highly consistent with the test.At the same time,based on the principle of symmetry and infinite ductility and considering the ease of imposing boundary conditions,a representative micro element structure is taken based on the micro honeycomb core.Using the homogenization theory combined with the finite element simulation,the macro-equivalent elastic parameters of the honeycomb core were deduced,and the honeycomb core was transformed from microscopic to macroscopic.Then,the finite element simulation of the CGF-PP skin of the sandwich structure is compared with the basic performance test of theCGF-PP skin.Finally,the three-point bending finite element model of equivalent honeycomb core and micro honeycomb core sandwich structure was established respectively,and compared with the three-point bending experiment.Combining mechanical performance analysis and finite element simulation,the following research results are obtained: Honeycomb core flat pressure finite element model and test error within 10%,when the honeycomb core is applied in a small area on the vehicle body,reference can be made to the establishment of the finite element analysis process.The error of CGF-PP skinning finite element simulation and test is only about 7.5%,which can well simulate and predict the deformation and failure of CGF-PP laminates.The three-point bending finite element model of the equivalent honeycomb core sandwich structure is compared with the three-point bending test of the sandwich structure with the same structure,and the peak force error is within 10%,and the deformation of the three-point bending finite element model of equivalent and micro honeycomb core sandwich structure is basically consistent.The computational efficiency of the equivalent honeycomb core sandwich model finite element model are more than 90 times that of the microstructure,which fully validates the effectiveness and high efficiency of the macro-equivalent model of the honeycomb core.