Wear resistance of bionic pitshaped middle trough based on response surface method

Scraper conveyor is an important piece of equipment to realize longdistance transportation of coal. The middle trough is its important component. It has been subject to a mixed friction of coal and scraper (scraper chain) for a long time,and its wear is very serious. To improve the wear resistance of middle trough,the nonsmooth pit structure on the surface of dung beetle is used as a bionic prototype,and with the help of bionic nonsmooth theory,a bionic pit structure is designed on the surface of middle trough,and the wear resistance of the bionic pit type middle trough is studied. Firstly,to explore the bionic parameters more efficiently,the reciprocating model of abrasive wear testing machine similar to the working principle of scraper conveyor is designed,and the DEM-MBD bidirectional coupling model of abrasive wear machine is established. The wear depth is analyzed by the EDEM discrete element,the relevant constraints are established by the RecurDyn multibody dynamics and the force analysis of the bionic middle plate is performed. Secondly,with the aid of response surface method,the parameter combinations of different pit bionic structures are screened to obtain the best parameter combination of wearresistant bionics. The results show that under the experimental conditions,the parameter combinations of the minimum wear depth of the pit bionic middle trough are as follows:shape round pit,diameter 0.9 mm,depth 1.8 mm,angle 90°,transverse spacing 13.6 mm,longitudinal spacing 10 mm,among which the diameter,depth and transverse spacing are significant factors. Thirdly,to verify the reliability of the simulation results,the bionic middle plate under the optimal wearresistant parameter combination is processed,and the wear resistance test is compared with the smooth middle plate. The results show that compared with the smooth middle plate,the pittype bionic middle plate has good antiwear performance,and the antiwear efficiency can reach 24.81%. In addition,the pit parameters are further verified by the simplified middle trough model in the same proportion as the SGZ880/800 scraper conveyor. It is found that the pit bionic structure under the optimal wearresistant parameters can effectively reduce the threebody wear between coal,scraper and middle plate,and the wear of middle plate is uniform,which further verifies the rationality of the combination of pit bionic wearresistant parameters. Finally,by analyzing its wear resistance,it is found that the pit structure can not only effectively reduce the contact area between bulk coal and middle plate and destroy the continuity of contact,but also form an air film on the contact surface between middle plate and bulk coal and reduce the friction coefficient.