## 3 Results and Discussion  
### Energy Conversion Analysis Based on FEM  
After ABAQUS software simulation and data processing, the internal energy change of a single kernel was shown in Figure 9, and the ear energy change was shown in Figure 10.  
According to Figure 9, the internal energy of the kernel with the greatest force initially increased, after which it decreased with collision time. The peak value of internal energy was 72.74 mJ when the damping unit was not added, and the snapping plate was fixed. After adding the damping unit, the peak internal energy was 59.95 mJ. In addition, the peak internal energy was reduced by 17.58% compared to the mechanism without the damping unit. The corresponding results demonstrated that the internal energy decreased significantly for the kernel with the greatest stress after adding the damping unit to the ear snapping mechanism. During the collision process, the change of ear energy when the ear snapping mechanism was not equipped with a damping unit was shown by the red curve in Figure 10. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Levels**} & \multicolumn{3}{c}{**Factors**} \\ \cline{2-4}  & **Rotational Speed** & **Forward Speed** & **Spring Stiffness** \\  & \(\mathbf{x_{1}/(r\cdot min^{-1})}\) & \(\mathbf{x_{2}/(m\cdot s^{-1})}\) & \(\mathbf{x_{3}/(N\cdot mm^{-1})}\) \\ \hline \(-1\) & 750 & 1.11 & 17.3 \\ \(0\) & 850 & 1.39 & 36.6 \\ \(1\) & 950 & 1.67 & 55.8 \\ \hline \end{tabular}
\end{table} 
Table 3: Factors and levels of test. Figure 9: Internal energy change of single kernel. Evidently, the ear kinetic energy started from 2000 mJ at 0 ms, which was followed by a steady rise to approximately 3043.61 mJ at 0.376 ms, in which the position potential energy of the ear was converted into kinetic energy. However, from then on, the ear kinetic energy sharply declined to 625.39 mJ at 0.726 ms. Since the collision was completed in an instant, the ear deformation reached maximum. At this time, the ear kinetic energy was converted into internal energy, and the ear kinetic energy dropped sharply. After that, the ear kinetic energy was on a steady rise to 1.776 ms, which then was kept stable. As the deformed ear part recovered, part of the internal energy of the ear was converted into kinetic energy; hence, the ear kinetic energy increased and then stabilized. Moreover, the ear internal energy started from 0 mJ at 0 ms, which was followed by a steady rise to 471.27 mJ at 0.376 ms as the ear deformation was small at the initial moment. However, from then on, the ear internal energy rose sharply to 2875.84 mJ at 0.726 ms. Since the collision was completed in a very short time, the ear deformation reached maximum, and the ear internal energy reached maximum at this time. Afterward, the ear internal energy was on a steady drop to 1.776 ms as the deformed part of the ear recovered and part of the ear internal energy converted into kinetic energy, which then stabilized. During the collision process, the change of ear energy when the ear snapping mechanism was equipped with a damping unit was shown by the blue curve in Figure 10.  
As shown, the ear kinetic energy started from 2000 mJ at 0 ms, which was followed by a steady decrease to approximately at 1779.23 mJ at 0.376 ms as the ear kinetic energy partially converted into elastic potential energy of the damping unit. The ear kinetic energy then declined sharply to 335.99 mJ at 0.876 ms. Since the collision was completed in an instant, the ear deformation reached the maximum. At this time, the ear kinetic energy was converted into internal energy, and the ear kinetic energy dropped sharply. After that, the ear kinetic energy was on a steady rise until 1.876 ms, and then kept stabilizes. As the deformed ear part recovered, part of the internal energy of the ear was converted into kinetic energy; hence, the ear kinetic energy increased and then stabilized.