A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of deser...A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.展开更多
The architecture of multilayer acting in colorful appearance has been widely reported.In spite of this,it is interesting that dense multilayer in epicuticle for Popillia indgigonacea Motsch elytra not only helps prese...The architecture of multilayer acting in colorful appearance has been widely reported.In spite of this,it is interesting that dense multilayer in epicuticle for Popillia indgigonacea Motsch elytra not only helps presenting angle dependence color-changing,but also showing higher reduced modulus(Er)and hardness(H)to protect soft abdomen below.The optical and nanomechanical properties of elytron were investigated by structural observation,optical experiments,nanoindentation and coupled bionic model simulations.The peak reflectance gradually varies from 588 nm to 510 nm with color change from orange and yellow to green when the incidence angle switches from 0°to 60°,which is attributed to the regulated variation from refractive spectra between the layers in different angle.In addition,the relatively higher Er and H of elytron epicuticle and endocuticle could play a role in resisting force with its multilayer.To identify the multifunctional characteristics of multilayer,optical and mechanical simulations were conducted based on coupled bionic models,and a strong consistence between the experiments and simulations is obtained.The multilayer could resist force with lowest strain and stress,and the structural thickness is the most necessary factors that could adjust the colors in color-changing process.展开更多
Based on the biological coupling theory, the resistance reduction characteristic of the surface morphology and surface wettability of the earthworm were studied in this paper. The parameters of surface dorsal pore and...Based on the biological coupling theory, the resistance reduction characteristic of the surface morphology and surface wettability of the earthworm were studied in this paper. The parameters of surface dorsal pore and corrugation were extracted. According to these parameters, the lubrication mechanism of the earthworm surface was analyzed. The distribution of the pores and surface morphology were designed and the bionic coupling samples were prepared. The positive pressure, lubricant flow rate and advancing velocity were selected as the experiment factors while the soil friction resistance as observed object. According to the obtained data of bionic coupling samples from the testing system of biologic signal for tiny soil adhesion test, the optimal samples from the bionic coupling resistance reduction tests were selected through the range analysis. Compared to the normal ones, the soil resistance of bionic coupling samples was reduced by 76.8%. This is of great significance and offers bright prospects for reducing energy loss in terrain mechanics.展开更多
基金Projects(51205161, 51175220, 51290292) supported by the National Natural Science Foundation of ChinaProjects(20120061120051, 20100061110023) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China+3 种基金Project(OSR-04-04) supported by Cooperation and Innovation to National Potential Oil and Gas for Production and Research, ChinaProject(200905016) supported by Ten Outstanding Youth Fund Project of Jilin University, ChinaProject(2012M511345) supported by China Postdoctoral Science FoundationProject(450060481176) supported by Basic Scientific Research Expenses of Jilin University, China
文摘A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.
基金This work was supported by National Natural Science Foundation of China(No.31970454)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education)of Jilin University.
文摘The architecture of multilayer acting in colorful appearance has been widely reported.In spite of this,it is interesting that dense multilayer in epicuticle for Popillia indgigonacea Motsch elytra not only helps presenting angle dependence color-changing,but also showing higher reduced modulus(Er)and hardness(H)to protect soft abdomen below.The optical and nanomechanical properties of elytron were investigated by structural observation,optical experiments,nanoindentation and coupled bionic model simulations.The peak reflectance gradually varies from 588 nm to 510 nm with color change from orange and yellow to green when the incidence angle switches from 0°to 60°,which is attributed to the regulated variation from refractive spectra between the layers in different angle.In addition,the relatively higher Er and H of elytron epicuticle and endocuticle could play a role in resisting force with its multilayer.To identify the multifunctional characteristics of multilayer,optical and mechanical simulations were conducted based on coupled bionic models,and a strong consistence between the experiments and simulations is obtained.The multilayer could resist force with lowest strain and stress,and the structural thickness is the most necessary factors that could adjust the colors in color-changing process.
基金supported by the National Natural Science Foundation of China (Grant No 50635030)the National Hi-Tech Research and Development Program of China ("863" Project) (Grant No 2010AA101401-3)
文摘Based on the biological coupling theory, the resistance reduction characteristic of the surface morphology and surface wettability of the earthworm were studied in this paper. The parameters of surface dorsal pore and corrugation were extracted. According to these parameters, the lubrication mechanism of the earthworm surface was analyzed. The distribution of the pores and surface morphology were designed and the bionic coupling samples were prepared. The positive pressure, lubricant flow rate and advancing velocity were selected as the experiment factors while the soil friction resistance as observed object. According to the obtained data of bionic coupling samples from the testing system of biologic signal for tiny soil adhesion test, the optimal samples from the bionic coupling resistance reduction tests were selected through the range analysis. Compared to the normal ones, the soil resistance of bionic coupling samples was reduced by 76.8%. This is of great significance and offers bright prospects for reducing energy loss in terrain mechanics.
