The Analysis And Simulation Study Of More Disc Grab's Efficiency For Viscous Powder

Grab is a kind of port instrument which is used to load and unload bulk-cargo.Because of that it has simple structure,flexible operation, stable and reliable working way, it becomes the main loading and unloading instrument in national bulk-cargo port. This paper does some research in terms of more disc grab's working to nickel ore in a port. Because the grabbing resistance has a decisive influence on the efficiency of grab,this paper analyze and calculate the scraping resistance,than research the influence of the three factors of the material granularity,adhesion and internal friction angel on the scrapping resistance torque.This paper's research content mainly has the following points.(1)This paper summarize the related research about grab.Summarize the development of grab,the scrapping resistance and the simulation of the grab's scrapping,then analyze the differences of all kinds of grab.(2)This paper do the kinematics analysis and simulation of the grabbing process.On the basis of kinematics, do the hypothesis that the up beam and the down beam have an uniform motion,and then get the kinematics mathematical model of the important dependent variable and draw the scrapping curve.Do the kinematics simulation of the grab's scrapping process with the ADAMS software,and get the changing rule of the three important dependent variable.(3)The scrapping mechanics model is established in this paper.Putting the more disc grab as the research object,based on the Rankine's earth pressure theory,combined with the structure of the more disc grab,analyze and calculate the cut-in resistance,frictional resistance,adhesive force,pushing resistance.Also according to the principle of function conservation,establish the mathematical relationship between the current of the motor which controls the grab to open or to close and the tension force of rope.According to the principle of moment balance,establish the scrapping mechanics model.(4)In order to check and correct the scrapping mechanics model,a test plan is designed in the paper.Design the test platform to measure the current of the motor for real-time monitoring of the scrapping operation,and then dispose the collected current date reasonably.Finally check and correct the scrapping mechanics model.(5)In this paper,do the simulation research of the scrapping process with MATLAB.Set up the simulation systems of the scrapping process with SIMULINK,researching the influence of the three factors of the material granularity,adhesion and internal friction angel on the scrapping resistance,and analyze the simulation results.