Mechanical Analysis And Optimization Of Asymmetric Honeycomb Sandwich Structure

The characteristics of the sandwich structure are higher rigidity and higher specific strength,and it can be designed and optimized according to the actual needs of the project.It can be widely used in various fields such as the transportation industry,construction industry,and electronic information industry.With the increasing diversification and extremes of engineering application environments,the engineering environment not only proposes bearing requirements for the sandwich structure,but also increases the indicators for satisfying specific functions at the same time.Therefore,different materials are applied to the upper and lower panels,respectively,resulting in asymmetry in the structure,which in turn affects the stiffness of its structural and functional integration.In this paper,theoretical derivation,numerical simulation and structural optimization methods are used to analyze and optimize the mechanical properties of asymmetrical honeycomb sandwich structures.The ultimate goal is to improve the bending capacity of asymmetrical honeycomb sandwich structures.The main research content of this paper is as follows:Firstly,based on the theory of material mechanics and mechanics theory of composite materials,the theoretical calculation formulas for strength,stiffness and weight of unsymmetrical sandwich structures were deduced,and the bending and weight characteristics of asymmetrical honeycomb sandwich structures were analyzed.The relationship between the structural bending stiffness and the thickness of the upper and lower panels,and the elastic modulus of the unilateral panel,were determined.At the same time,finite element simulation of an asymmetrical honeycomb sandwich structure shows that the structural bending stiffness obtained through finite element calculation and the design value error of the structural bending stiffness are within the allowable error range of the engineering,which ensures the accuracy of the study.Secondly,the finite element simulation modeling software was used to simulate the mechanical properties of asymmetric honeycomb sandwich structure.It was found that when the panel thickness ratio was changed in the range of 0.5 to 1,the drop in the structural bending stiffness was more pronounced than when the E/Ef1 was varied in the range of 0.5 to 1.However,when the asymmetrical side panel drops below 0.5 times the original thickness,the panel's properties become the main factor affecting the bending stiffness of the structure.Therefore,geometric asymmetry and material asymmetry are the main factors that affect the bending stiffness of the structure for different changes.Finally,the effects of bending stiffness of different schemes were studied from several angles such as panel thickness matching,panel ply design,honeycomb shape selection and core wall thickness.Comparing with the design scheme of pure vertical lay-up,the structural bending stiffness of other lay-up design schemes has decreased.Sacrifice the thickness of the core in the range given in this article,can maximize the structural bending stiffness of about 8%,while the thickness of the panel is designed by the panel thickness matching method,a larger range of target structure bending stiffness can be achieved,and there are multiple solution.Compared with Kagome honeycomb and regular hexagonal honeycomb,Kagome honeycomb can increase the bending stiffness of the structure by 32%~67% in the wall thickness range of this chapter under the same wall thickness conditions;in the wall thickness range of this chapter under the same core volume condition the internal Kagome honeycomb can increase the structural bending stiffness by 20% to 40%.When the material of the honeycomb core is different,the bending stiffness of the structure is also affected by the wall thickness of the core.For a honeycomb structure using aramid paper as a raw material,the bending stiffness and the specific stiffness of the asymmetric honeycomb sandwich structure follow with the increase of the wall thickness,the asymmetrical honeycomb sandwich structure made of metal aluminum,the variation of the specific stiffness is increased first and then decreased.