Simulation test and analysis of grinding wheel of desert grass square-lattice paving integrated machine

Objective Grass square-lattice sand barriers is is a mechanical sand-fixing method for suppressing the wind speed by pressing rice straw into the desert. In order to reduce labor intensity and improve efficiency，mechanized operation is adopted.However，the straw dynamics of micro-mechanism changes during the paving process are not clear，it is easy to push the grass during the grass pressing process，the uniformity is not stable and the grass roller is easy to wear out. Method Using finite element simulation and theoretical analysis combined with the structural check analysis of the grass roller，the sand-straw-grass roller interaction system model was established based on the discrete element（EDEM）simulation software.Based on the variation law of simulation，the micro-dynamic interaction mechanism and the wear of the grass roller were studied. Result The simulation results showed that the structure design of the grass roller met the requirements and effectively solves the problems of pushing grass；the wearable area was in the serrated tip of the outer edge and the reinforcing rib，and the sliding friction generated by the slip exacerbated the wear of the roller；the operation quality of the serrated grass roller was better than that of the disc shaped grass roller，and the pass rate of the grass roller can be effectively increased by 11.4%；the sand and soil disturbance profile generated by the grass roller process was close to the V-shape of the soil touching portion of the grass roller.The sand disturbance profile generated during the grass compaction process was close to the V shape of the grass compaction wheel.The higher the speed caused the higher sand disturbance and the higher wear of the grass compaction wheel，which maded the qualit of paving more unstable. Conclusion The simulation model presents the motion characteristics of straw，sand particles and grass roller in the microscopic operation process，the discrete element method is applied to compare the simulation of the grass roller process with the actual operation effect，and the simulation results are basically consistent with the field test conditions in the desert，which verifies the feasibility and reasonableness of the design of the grass roller as well as the accuracy of the simulation model，and it provides a new method and a new reference for the sand control and compaction machinery.