For studying the working performance of the cutting header, the paper puts forward using DEM to study its dynamic breaking process when it is for cutting coal rock. The model of cutting header and the model of the two-dimensional DEM simulation analysis are set up separately. By applying reasonable mechanical model into coal rock particles and the cutting header, DEM simulation analysis of its cutting process is carried out. Such analysis is taken at different cutting speed. Then, the way of selecting working parameters is got. It preliminarily proves the feasibility of using DEM to analyze the working procedure of the cutting header and it provides a new research method for its optimization design.

Flow behavior of particles is simulated by means of discrete element method (DEM) in a screw conveyor. The gas flow is considered by the Euler model. The subgrid scale model turbulence model is applied to solve gas turbulence. A detailed description of the model equations applied has been presented.The comparison between computational fluid dynamics (CFD)-DEM (i.e., considering gas flow) and DEM (i.e., not considering gas flow) simulation results is performed. Predicted mass flow rate with CFD-DEM model is in better agreement with experiments by Roberts and Wills comparing with DEM results. The effects of incline angle and filling rate on the flow behavior of particles are predicted. The simulation results show that the gas flow has a major impact on particle flow behavior at a high rotation speed, whereas the velocity of particles increases with an increase of rotation speed. As the filling rate rises, both the translational granular temperature and the rotational granular particle temperature decline, which means that the particles fluctuation turns weak. While with an increase of incline angle, from the horizontal to vertical, the translational granular temperature is increased, but the rotational granular temperature reduces and then goes up. In brief, translational motion is a main mode of motion in a screw conveyor. K E Y W O R D SCFD-DEM, filling rate, gas-solid two-phase flow, incline angle, screw conveyor

The paper adopts multi-boy dynamics software and simulates and analyzes the banana type vibrating screen. The paper obtains the result of vibration amplitude of vibrating screen at its working through computing；we can get the resonance by analyzing the amplitude curve , which is a significant guidance for design, improvement and maintenance.

In the millions of years plants continue to develop and evolve for the competition of survice, the macroscopic and microscopic structure and morphology of plants may seem simple, but its specific functions, is man-made design unmatched. By observing the distribution of plant leaves, bionic design of the picks on cutting head based on phyllotaxis theory and establish its 3D model ,which fills its gap in the field of bionic design.

Seed metering procedure of metering device was a key factor to affect performance of precision seed metering device. Based on analysis of seed holding volume of metering scoop, relationship between the seed holding volume and structure parameters of the metering scoop was established, and beginning and ending angles of seed clearing during the seed metering procedure were determined. Simulation analysis of seed metering procedure with different parameters of the metering device was carried out by mean of discrete element method to identify the influences of metering scoop parameters on the performance the metering device, and suitable range of structure parameters of the metering scoop were investigated. Finally, the reasonability of design parameters of the metering scoop for experiment usage was verified.