## 6 Conclusions  
(1) The bending angle is one of the key structural parameters that affect the performance of the rotary blade. When the bending angle is 110-130\({}^{\circ}\), the structural stress and bending deformation increase with the increase of the bending angle. When the bending angle is 110\({}^{\circ}\), 120\({}^{\circ}\), and 130\({}^{\circ}\), the average deformation is 0.94 mm, 1.13 mm, and 1.22 mm, and the average stress is 39.67 Mpa, 45.39 Mpa and 50.98 Mpa, respectively. The analysis results provide reference for the subsequent structural parameter optimization.  
(2) Through the use of the discrete-element simulation method, we carried out cutting simulation and process analysis. Using the design of experiments method to establish the tool's roll cutting power consumption, the fitting equation and mathematical model can better predict the power consumption. The established cutting power fitting equation and mathematical model can better predict power consumption. Considering the structural performance, actual production, and application of the rotary blade, the optimal parameters were determined as follows: forward speed 899.96 m/h, rotation speed 100.93 r/min, and bending angle 116.43\({}^{\circ}\). The corresponding minimum power consumption was 1.44 kW, the average deformation of a single rotary blade was 0.983 mm, and the average stress was 41.826 Mpa, which were reduced by 15.8%, 13%, and 7.9%, respectively. Through the comparison of the field experiment and 17 groups of simulation experiment data, the error of the actual power consumption and the simulation experiment was lower than 12%, and the structural performance met the requirements of rotary tillage intensity.  
(3) The optimal parameters obtained from experiment optimization were verified by the simulation experiment and the field experiment. The power consumption was 1.55 kW and 1.6 kW respectively, which was 9.4% and 6.4% lower than that under the initial parameters. The structural performance of the optimized rotary blade was evaluated by the finite-element method, and the calculated results met the mechanical requirements of the rotary blade. The overall optimization results achieved effective reduction of power consumption, in line with the green development direction of agricultural machinery.  
Conceptualization, X.Z. and L.Z.; methodology, X.Z.; software, X.Z.; validation, X.S., X.M. and H.W.; formal analysis, H.W.; investigation, X.Z.; resources, X.Z.; data curation, X.Z., X.H. and H.W.; writing--original draft preparation, X.Z.; writing--review and editing, L.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Construction Project of Demonstration Platform for National New Materials Production and the Application-Demonstration Platform for Production and Application of Materials on Agricultural Machinery Equipments, grant number TC200H01X-5.  
Not applicable.  
All relevant data presented in the article are stored according to institutional requirements and, as such, are not available on-line. However, all data used in this manuscript can be made available upon request to the authors.  
The authors declare no conflict of interest.