Research On Bionic Design And Energy Absorption Characteristics Based On The Thin-walled Structure Of Bean Goose(Anser Fabalis) Feather Shaft

With the improvement of light weight and energy absorption performance requirements,it is important to improve the energy absorption efficiency of thin-walled structures while ensuring their strength and rigidity.After millions of years of natural selection,organisms in nature have evolved biological structures with excellent mechanical properties.Among them,the bean goose has excellent flight performance and is good at long-distance flight.Its feather shaft has the advantages of light weight and high strength,which provides a reference and theoretical basis for the design of light and thin-walled energy-absorbing structures.In this paper,the bean goose shaft was selected as the research object based on the principle of engineering bionics.The macroscopic and microscopic structures of the feather shaft were observed by scanning electron microscope and ultra depth of field microscopic system.The composition of its feather shaft was measured by Fourier transform infrared spectrometer.Through the quasi-static axial compression test,the compression performance of the rachis in different parts of the bean goose was studied,and it was found that the mechanical properties of the primary flight feathers were relatively better.Furthermore,the compressive properties of N1-N8 samples in different regions along the fiber direction of primary flight feather were studied.Compression tests were performed on the rachis specimens with medulla and without medulla(only containing cortex)by a small electronic universal testing machine,verifying that under the synergistic effect of cortex and medulla,its compressive performance is the best good.The energy absorption and bending resistance of the specimens in different regions were obtained by the three-point bending tests on the fiber-oriented continuous three-segment specimens of the primary feather shaft.Comprehensive analysis shows that the mechanical performance of the N3 area of the primary feather shaft is better.Three-dimensional reconstruction of the microstructure of the optimal area(N3)was performed through the results of the Micro-CT scan,and two structural characteristic parameters of "sawtooth" and "semicircle" were obtained.A finite element model is established to analyze its energy-absorbing structure,and it is found that these two structures play a key role in the compression resistance and energy-absorbing efficiency of the rachis.Based on the above research,five design schemes of the bionic thin-walled structure were proposed.The compression simulation was carried out by combining Hypermesh and Ls-dyna,and the optimal bionic design scheme was selected as the aluminum foam-filled thin-walled structure with approximately square outer contour and zigzagged inner contour.Six kinds of tube models were fabricated by machining.The axial quasi-static compression test was carried out,and the test results confirmed the feasibility of the design.Finally,a new bionic thin-walled structure is obtained.In summary,this thesis combines biology and structural design,uses a variety of testing techniques,studies the mechanical properties of the structure based on the light weight and high strength characteristics of the bean goose feather shaft,designs a new type of light and energy absorption bionic thin-walled structure,and proves its feasibility by the method of simulation and experiment.Under the premise of ensuring lightweight,the bionic structure improves the energy absorption of traditional energyabsorbing structures.This paper can provide a technical reference for the further development of the design and research of the bionic thin-walled structure.