Research On Optimization And Mechanical Properties Of Aircraft Structural Parts Based On Bionic Lightweight Structure

For the aircraft,reducing the quality of the structure means that the payload,flight speed and flight distance increase.The importance is self-evident.Therefore,the lightest weight of the structure has always been one of the goals pursued by the aircraft structure design.The missile-stage is the connecting component between the multi-stage missile sub-class and the sub-level.However,the traditional interstage structure is often not very effective in reducing the weight of the inter-stage segment.Therefore,a new solution is urgently needed.Recent studies have shown that porous glass sponges are a typical porous lightweight structure with good mechanical properties.Therefore,this paper chooses porous glass sponge as a biomimetic template,and optimizes the design of an aircraft-stage segment to provide new ideas and methods for grid structure design on the aircraft.In this paper,the cell structure I of the porous glass sponge is taken as the design element,and the lightweight is the main goal.Five kinds of central angle corresponding to cell structures are determined,and five kinds of bionic grid structures I are designed.The ANSYS workbench software is used to analyze the five structures and compare with the traditional upright orthogonal grid structure.It is found that the five bionic grid structures I can achieve the goal of lightweight without affecting the static and mechanical properties of the structures.In this paper,a bionic grid structure I is selected to analyze the effect of longitudinal and oblique ribs on the strength,stiffness and buckling performance of the structure.The analysis results are taken as the design basis,and then the rib layout of the bionic grid structure I is optimized to obtain the bionic grid structure II.Due to the importance of buckling stability to the lattice structure,the buckling failure modes and mass efficiencies of the bionic grid structure II under different structural forms are studied,and the optimal central angle and the spiral angle range of the oblique ribs are obtained.In this paper,it is found that the opening area of the interstage is the weak point of its strength,so the opening rib is designed to strengthen the strength of the opening area.The parameter optimization model of the bionic interstage is established.With the mass,max stress and max axial deformation of the upper end face as the optimization objects,the multi-objective drive optimization design is carried out to obtain the optimal size parameters.The results show that on the premise of meeting the requirements of use,the structure design of the imitation glass sponge interstage is well achieved.