Research On Extracting Anti-fatigue Coupling Element And Designing Bionic Sstructure

Because the aircraft will be subjected to complex alternating loads during long-term flight,it will often occur cracks in the aircraft's skin and cause serious flight accidents.Therefore,in order to improve the crack resistance of the aircraft skin and effectively improve its residual fatigue life,based on the plant blade,this paper carried out a study of the bionic unit to retard the crack growth.Firstly,in order to extract suitable bionic parameters of leaf vein anti-crack structure,optimized digital image processing technology was used to extract the angle and distribution information of leaf veins from 210 plant leaves and Statistically optimized bionic parameters are used to generate leaf vein bionic units.Then the Lloyd algorithm was used to generate the centroid Voronoi diagram within various shape boundaries,approximate the Voronoi structure of insect wings by controlling the roundness,number,and iteration times of the cell.and then that structure and the leaf vein bionic unit were combined to generate leaf vein-wing bionic coupled model and low-cycle fatigue numerical simulation was carried out to determine the fatigue resistance and stress distribution of the bionic model.In order to explore the effect of the leaf vein bionic unit on the crack resistance of the aircraft skin based on aircraft skin damage repair,the laser cladding technology was used to prepare the leaf vein bionic unit on the 2024 aluminum alloy.The fatigue life and crack growth rate of the vein bionic unit with different parameters bionic samples and untreated samples through mechanical fatigue experiments under constant amplitude load.Finally,analyzing the crack propagation path,observing the macro and micromorphology of the fracture section of the sample,measuring the hardness of the leaf vein bionic unit were used to explore the mechanism of the leaf vein bionic unit blocking crack growth.it shows that the special structure and hardness of the leaf vein bionic unit have It is the main factor that retards crack propagation.