Structural Analysis Of Supporting Arm Of The Canopy Of A Certain Type Of Aircraft Considering The Influence Of Deformation Of Fixture

The supporting arm of canopy is an important connection structure between the canopy and airframe,and its strength and rigidity under the working environment must be guaranteed.In order to analyze the rationality of the design of the supporting arm of canopy and the safety of use,this paper analyzes the structure of the supporting arm of canopy and verifies the correctness of the analysis results by static tests.Firstly,the CAD software,CATIA,is used to establish the model of the supporting arm of canopy,and simulate the actual connection conditions of the supporting arm of canopy and other aircraft parts,and design static test fixtures.The finite element software,Abaqus,is used to complete the strength analysis of the static test fixture.According to the strength analysis result,the corresponding thermal treatment method is selected for the manufactured static test fixture to ensure the safety of the test fixture.Secondly,appropriately simplify the structure of the test fixture and the supporting arm of canopy,and retain the main load-bearing structure.The part that do not affect the main mechanical properties are ignored,for example,holes,bolts,arcs and chamfers.Use CAE software,HyperMesh and Abaqus,to build Finite element analysis model of the supporting arm of canopy and its fixture.The statics test fixtures are given two different properties,elastic body and rigid body,and the statics analysis of the supporting arm of canopy of the aircraft is carried out.The strength and stiffness is obtained that the canopy arm is under the limit load（19902N）and ultimate load（29853N）of the operating conditions.The results show that the deformation of the static test fixture has little effect on the stress,strain and displacement of the supporting arm of canopy,,and meets the design requirements of the static test fixture,and verify the rationality of the design of static test fixture.Thirdly,use the microcomputer-controlled electronic universal testing machine（WDW-100E）to carry out the statics test of the supporting arm of canopy to verify the correctness of the finite element analysis results.The results show that the results of the finite element analysis are in good agreement with the test results.The maximum stress of the canopy arm under the ultimate load is less than the tensile strength of the material.The static strength of the supporting arm of canopy meets the requirements of use.Finally,the free modal analysis and constrained modal analysis of the supporting arm of canopy are done to research the natural frequency and mode shape of the supporting arm of canopy.And,on the basis of constrained modal analysis,the random vibration spectrum is loaded by defining the power spectrum density PSD of accelerated velocity in Abaqus to analyze the strength and rigidity of the supporting arm of canopy under random vibration.