Research On Bionic Design Of Shovel Excavation Components And Its Performance Of Drag Reduction And Desorption

As one of the typical soil-contacting components,the shovel excavation component has the problems of excessive working resistance and serious soil adhesion,resulting in reduced work efficiency and shortened service life.As the same time,it also caused huge energy and environmental pollution and hindered the development of agricultural mechanization.Traditional solutions,such as improving the structure,adding vibration devices and coating materials,have problems such as additional power consumption,complicated mechanism redundancy,or poor wear resistance of the surface coating.After hundreds of millions of years of evolution,organisms have been well adapted to the natural environment.By learning to imitate its own structure and body surface shape,the drag reduction and desorption of shovel excavation components can be achieved,which is of great significance for energy saving and efficiency improvement of agricultural machinery and improving work quality.Therefore,in this paper,the pangolin is used as a bionic prototype to study the drag reduction and desorption of shovel excavation components.The details are as follows:(1)The contour structure and scale surface morphology of pangolin claw and toe were studied.The inner and outer contour curves of the claw toe were extracted by Auto CAD and Creo 7.0 software,and the contour equations were obtained by fitting.The experimental soil tank was established by using EDEM discrete element software,and the basic parameters of soil particles,geometry and contact model were set.By comparing the excavation of two types of claw toe models at different excavation depths,the drag reduction performance of the inner ridge structure of the claw toe was analyzed.The non-smooth feature structure of the scale surface was observed,and the scale image was grayscaled by MATLAB.The statistical law of the grayscale value distribution of the scale grayscale image was further extracted and studied.The results showed that the scale surface had fractal characteristics.At the same time,the hydrophobic properties of the scales also help them achieve drag reduction and desorption.(2)Based on the inner and outer contour fitting equation of pangolin claws and toes,the bionic surface of the shovel excavation component was designed,and parameters such as the entry angle were determined by analyzing the force of the shovel excavation component in the soil.The bionic ridge structure with different parameter combinations was designed on the upper shovel surface by orthogonal test,and the optimal parameter bionic shovel-type components were obtained by testing and comparing the working resistance of various excavating shovels in EDEM discrete element software.The bionic shovel parts and ordinary shovel parts with optimal parameters were processed by 3D printing technology,and the working resistance was tested and compared in the indoor soil tank.The results showed that the average drag reduction rate of the bionic shovel parts was 16.5%,and the bionic design effectively reduced the resistance.(3)Based on the fractal structure and hydrophobic properties of pangolin scales,a similar microstructure was constructed on the surface of 65 Mn by a laser marking machine,and a soiladhesion-resistant surface with superhydrophobicity was prepared after modification with stearic acid.The effects of different laser processing parameters on the surface wettability of the prepared samples were studied by orthogonal experiments,and the optimal level of each laser processing parameter was determined by range analysis,and the effects of surface morphology and chemical composition of the samples on wettability were studied.The soil adhesion force on the surface of the samples was determined by the pull-off method.(4)The fractal characteristics of the prepared sample surface were studied,the fractal dimension of the sample surface was calculated by the box dimension method,and the relationship between the fractal dimension and the wettability of the sample surface was studied by changing the laser processing parameters.The mechanical stability of the sample surface was tested by the linear wear test.By observing the surface morphology of the sample before and after wear and calculating the fractal dimension,the influence of the fractal structure on the mechanical stability of the sample surface was analyzed.