Research On Simulation Method Of Aero-Engine Bolted Connection Structure Based On Thin Layer Element Method

In the finite element analysis of aero-engine bolted connection structure and the whole machine finite element analysis,the model quality of bolted connection structure plays an important part.In traditional finite element modeling analysis,the fine finite element model is mostly used.This model fully retains the geometric features of the structure,but it needs smaller unit sizes for mesh generation,resulting in huge numbers of cell.Contact surface and preload force make the analysis process nonlinear,which increases the computational complexity and difficulty.Therefore,the thin layer element method based on isotropic material is studied,and an improved method is proposed,which is applied to the modeling and simulation of aeroengine bolted connection structure.Through this research,it aims to provide an idea for the modeling and simulation of aero-engine bolted connection structure,improving engine simulation efficiency.The main contents of the paper are as follows:Firstly,the thin layer element modeling and simulation method is studied,which adopts isotropic material.By deriving the modeling principle of the thin layer element of isotropic material,the mathematical expression of the rigidity of the aero-engine bolted structure is calculated,which theoretically verifies the feasibility of the thin layer element method and determines the material parameters of the thin layer element.The comparison of the modeling and simulation processes,simulation analysis results and calculation time with the fine finite element modeling and simulation method as the standard are studied to verify the feasibility in modeling and simulation of the thin layer element method.Secondly,aiming at the deficiency of the thin layer element method in simulating the stress distribution on the connection surface of the bolted connection structure,the variation regularity of the axial stress of the bolted connection surface is studied by stress analysis,and the improved thin layer element modeling and simulation method is proposed to determine its material parameters.The correctness of the improved method is verified through simulation analysis.Lastly,three modeling and simulation methods are applied to an actual structure.The fine finite element model results are taken as the standard values.The feasibility of the thin layer element method and correctness of the improved thin layer element method are verified comprehensively through static analysis,modal analysis and thermal-structural coupling analysis.The results show that the thin layer element method simplifies the process of modeling and simulation,which has a fast calculation speed and can simulate the aero-engine bolting structure.Meanwhile,it has obvious advantages in the overall structure deformation distribution gradient display,and the improved thin-layer element method can better simulate the aero-engine bolted structure,the error of the analysis results can be reduced by up to 6% in various working conditions.