Bionic Study On Body Surface Erosion Resistance Of Semi-desert Parabuthus Transvaalicus

When two or more parts are in relative motion on the contact surfaces,the wear is caused by friction,which directly leads to the reliability and service life of the parts,the low work efficiency,the increase of the consumable parts,etc.,which indirectly leads to energy loss,increased maintenance costs,and low economic efficiency.Erosion is an important branch of the wear field.It is widely applied to many domains,including wind turbines,compressors,flotation machines,drill strings,screens,logistics pipelines,turbine engines,etc.,which caused great inconvenience and harm to human production and life.At present,composite materials,surface coatings,surface modification and other methods have been widely used in materials to improve the erosion resistance of materials.However,these methods can reduce erosion to a certain extent,but considering the manufacturing technology,manufacturing process,cost and green development,they are not good enough to achieve the desired results.Therefore,whether it is from the perspective of energy conservation or the reliability of parts and the efficiency of production,it is extremely urgent to find a more convenient and adaptable method for erosion resistance.Inspired by bionics,Parabuthus transvaalicus,a scorpion found in semi-desert,was chosen as biological prototype.The morphological characteristics of the back of the scorpion were analyzed by various microscopes,and the typical structures and the relevant dimensional parameters of the back of the scorpion were extracted.It was found that the width of seven terga of the scorpion were different.The surface of the seven terga are distributed with convex hulls,which were different sizes and uneven.In addition,the convex hulls on both sides of the seven terga are dense,and the middle is sparse and three ridges are formed.The seven terga of the scorpion are connected through intersegmental membrane,which form natural V-grooves on the surface.In terms of the width of the V-grooves increases first and then decreases,while the height shows a trend of decreasing first and then increasing.The back of the scorpion is an arc-shaped structure with curvature,and the curvature of the middle portion is larger than the curvature of the both sides.The erosion resistance performance of the scorpion is closely related to the material itself.Therefore,the mechanical properties,cross-section structures and chemical compositions of the seven terga and intersegmental membranes on the back of the scorpion were studied.It was found that the elastic modulus and Young's modulus of the tergum were smaller than the intersegmental membrane.The cross-section of the tergum and intersegmental membrane are layered,the endocuticle is the thickest,and there are hollow pipes and porous structures,which can transport nutrients and absorb excess energy,and have a stress-releasing effect.The main difference between the tergum and intersegmental membrane cross-section structure is the layer thickness.The main elements of the tergum and intersegmental membrane are C,N,and O.For a small amount of metal and non-metal elements,the intersegmental membrane has no Mg and Fe elements.The tergum is mainly composed of organic molecules such as chitin,and the intersegmental membrane is mainly composed of protein organic molecules.Based on the distribution characteristics of the convex hulls structure on the back of the scorpion,six different bionic convex hulls structure erosion-resistant geometric models were designed by using the principle of similarity and functional principle.The ANSYS-FLUENT simulation software was used to test these geometric models.The solid bionic convex hulls structural samples were printed by 3D printing technology,and the erosion tests were carried out by the sand-blasting machine.The erosion test results were consistent with the simulation test results,indicating the correctness and reliability of the test,the optimal geometric model was obtained.According to the convex hulls structure and V-grooves structure on the back of the scorpion,in order to explore the influence of different structures and size parameters on the erosion performance of the samples,the bionic composite structural samples of different sizes were further designed,and the physical samples were printed and tested.The primary and secondary factors affecting the erosion performance were obtained by the test results.In order to explore the effects of different speeds and different angles on the erosion performance of bionic specimens,combined with the best samples tested in erosion wear test,a blank test specimen was designed to test.It was found that the erosion performance of the bionic specimens were better than that of the blank test specimen,and the general trend of erosion performance of the specimen was exponential.In addition,the erosion rate of the sample increased with the increase of the rotational speed and increased with the increase of the angle.That is,the erosion rate of the sample at different speeds and different angles is the lowest at 30°,the maximum at 90°.