# Design of Man-Machine Synergic Lunar Coring Device and Its Coring Dynamic Analysis
## 4 Dynamic Analysis and Verification of the Coring Device
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \begin{tabular}{c} **Density** \\ \(\rho\) (kg/m\({}^{3}\)) \\ \end{tabular} & \begin{tabular}{c} **Shear Modulus** \\ **G (GPa)** \\ \end{tabular} & \begin{tabular}{c} **Tensile Strength** \\ **T (MPa)** \\ \end{tabular} & \begin{tabular}{c} **Compressive Strength** \\ **\(f_{\epsilon}\) (MPa)** \\ \end{tabular} & \
\begin{tabular}{c} **Modulus of Elasticity** \\ **E (GPa)** \\ \end{tabular} &
\begin{tabular}{c} **Poisson’s Ratio** \\ **\(\mathbf{\
u}\)** \\ \end{tabular} \\ \hline
2164 & 4.437 & 1.107 & 70.27 & 12.27 & 0.38 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Basic physical and mechanical parameters of simulated lunar rock. Figure 10: (a) Torque boundary conditions for structural parameters of the impact module; (b) Energy release boundary conditions for structural parameters of the impact module; (c) Maximum impact energy under boundary constraints. the coring tube, as shown in Figure 11a. When using rotary drilling for coring, only a certain amount of rotational speed is applied to the drilling tube. The sampling method is converted to impact-drilling, as shown in Figure 11b, where additional impact energy is applied to the drill tube to achieve a more significant impact-crushing effect. After setting various parameters, the simulation analysis was performed for different coring methods. In the simulation, the impact energy (14.9 J) released by the impact hammer was applied to the coring tube with a loading time assumed to be 5 ms. During the process of impact energy loading, the coring tube has a certain impact effect on the simulated lunar rocks. However, the impact energy alone could not induce significant deformation of the simulated lunar rocks, with a maximum plastic deformation of only 0.029 mm and without the desired impact-crushing effect (Figure 12a). Even if a certain rotation speed is applied based on impact penetration, the crushing effect of the coring tube on the simulated lunar rocks is not very obvious, and the maximum plastic deformation is only 0.042 mm (Figure 12b). The actual geology of the moon is very complex, and the impact penetration method simply cannot penetrate the rock for sampling. Therefore, the coring device must replace the coring tube with an auger tube when facing hard lunar rocks. Compared with the coring tube, the drilling tube has a significant crushing effect on the simulated lunar rocks during rotational drilling, and the maximum plastic deformation of the rocks can reach 0.35 mm within a loading time of 5 ms (Figure 12c). When a certain amount of impact energy (14.9 J) is added to the rotation drilling process, the sampling method will be converted to impact drilling type, and the crushing effect on the simulated lunar rocks will be significantly increased. The maximum plastic deformation of the simulated lunar rocks can be increased to 0.47 mm during the loading period (Figure 12d). Therefore, according to the sampling environment, choosing the appropriate sampling method can improve sampling efficiency, ensuring the work is safe and stable. In summary, the magnitude of the impact energy (5\(\sim\)15 J) is closely related to the structural parameters of the impact module and the impact frequency. In addition, the impact frequency also affects the response speed of the impact energy. The impact frequency can be adjusted within 0\(\sim\)20 Hz, and the increase in the impact frequency can effectively destroy the formation of internal stress in the coring tube and improve the coring rate. Although the coring tube under the action of impact energy can achieve the sampling of lunar regolith, the simulation results show that the coring tube cannot penetrate the rock. Therefore, only with the combined effect of impact energy and rotation speed can the drilling tube achieve a significant crushing effect on the lunar rock. In addition, the impact frequency and rotation speed are adjustable to suit different sampling environments.