Structure Design And Optimization Analysis Of Composite Landing Gear

The landing gear is a key component to ensure the safe flight of the aircraft.It canabsorb and dissipate the impact energy formed by the aircraft during landing and taxiing,which is very important for the overall performance and safety of the aircraft.As composite materials are used more and more on aircraft,composite landing gears,which are the main bearing components,have also begun to appear on some foreign fighters.The mechanical properties and damping characteristics of the landing gear are two important parameters for studying the technical level and reliability of the landing gear.Therefore,it is very important to study the damping characteristics of the composite landing gear.In this paper,based on the damping characteristics of composite landing gear,the combination of numerical simulation and experimental verification is used to study how to improve the damping characteristics of the structure through optimization design.This paper firstly uses the ABAQUS finite element software to establish the metal landing gear model with reference to an Unmanned Aerial Vehicle landing gear,and analyzes the mechanical performance of the shutdown and landing process.Based on the metal landing gear,the finite element model of the composite landing gear was established.On the basis of satisfying the strength and stiffness,the simulation results of the composite landing gear are compared with the calculation results of the metal landing gear.It is found that the displacement of the composite landing gear is less error compared with the metal landing gear,and the trend of velocity and displacement with time is consistent with the metal landing gear.On this basis,the modal analysis of the composite landing gear is carried out,and the frequency,stress,strain,strain energy and mode shape of each mode can be obtained.On the basis of modal analysis,combined with the modal strain energy analysis method of composite structure,the damping loss factor of various modal modes of composite landing gear is obtained by using Python language programming program,and the damping characteristics are analyzed.After the damping characteristic analysis is completed,the damping characteristics of composite landing gear are optimized by Isight optimization platform for the layup angle of composite landing gear,carbon fiber/glass fiber ratio and structural size.Finally,an optimal composite landing gear structure is obtained.According to the structural characteristics and laminate design of composite landing gear,combined with the characteristics of different composite moldingprocesses,the high-performance epoxy resin is used as the matrix,and the carbon fiber reinforced composite material and glass fiber are used as the reinforcement to carry out the composite landing gear.After the structure is completed,the force hammer method is combined with the dynamic signal processing system to carry out experimental research on the composite landing gear structure.The vibration frequency and mode shape of each mode of the structure are obtained through experiments and the structural damping loss factor of the composite landing gear is calculated by statistical energy analysis method.Comparing the finite element simulation results with the experimental results,the difference between the two is small,and the change trend is consistent,thus verifying the validity of the finite element analysis.