# Launch Performance Degradation of the Rupture-Type Missile Canister
## 6 Conclusions  
The effect of the rupture-type missile canister cover was investigated, while interfering with the neighboring structures, for the case when it is not fully ruptured, and some remnants are present. We also examined the impact of the phenomenon on the ejection performance of a missile by simplifying the shape of the canister cover in the analysis model. A CAE based analysis was then performed and the effects of the cover remnant, material deterioration, and material property variation at high-speed were obtained. Firstly, no interference between the support ring and missile occurred when the fastening part used for fixing the support ring and frame is normally established. If there is an abnormality in the installment of the fastening part, then the cover residue collides with the missile sabot causing the support ring to deform. From both the simulation and experimental results, we demonstrated that interference can occur with the missile booster. Secondly, the deterioration of the sabot, which is made of urethane foam, due to long-term storage did not cause any severe problems to the missile launch performance. We confirmed that the urethane foam deteriorates if damaged early; however, it contributes less to the deformation of the support ring. Thirdly, the material property variation in high-speed resulted in a deeper deformation of the support ring due to an increase in the urethane foam stiffness. When the high-speed properties are reflected, the stiffness is increased and so the missile sabot pulls the support ring for an extended period. This results in an increase in the support ring deformation. In summary, we concluded that the missile launch performance, for the specific rupture-type missile canister case, could be degraded due to two main causes: (1) the deflection of the support ring after the elimination of fasteners and (2) the material property variation in high-speed. The simulations can be viewed at the following YouTube URLs: Figure 3 at [[https://youtu.be/hPQDTxLn58w](https://youtu.be/hPQDTxLn58w)]([https://youtu.be/hPQDTxLn58w](https://youtu.be/hPQDTxLn58w)), Figure 7 at [[https://youtu.be/](https://youtu.be/)]([https://youtu.be/](https://youtu.be/)) \begin{table}
\begin{tabular}{l l l l} \hline \hline  & **Analysis** & **Test Result** & **Impact Factor** \\ \hline \multirow{6}{*}{Cover Remnant} & Deflection of the Support Ring & \begin{tabular}{l} Increase in the number of bolts reduced the deflection of the support ring. \\ \end{tabular} & High \\ \cline{2-4}  & \multirow{2}{*}{Effect of the Cover Residue Height} & \begin{tabular}{l} Portion protruding beyond the groove height does not \\ significantly affect the deformation of the support ring or \\ behavior of the missile sabot. \\ \end{tabular} & Low \\ \cline{2-4}  & \multirow{2}{*}{\begin{tabular}{l} Deflection of the Support Ring \\ under the Elimination of Fasteners \\ \end{tabular} } & \begin{tabular}{l} Deformed support ring could interfere with the missile \\ booster wing during missile release. \\ \end{tabular} & High \\ \hline Material Deterioration & \multirow{2}{*}{\
\begin{tabular}{l} The urethane deterioration does not cause a fundamental problem. \\ \end{tabular} } & Low \\ \hline Material Property Variation in High-Speed &
\begin{tabular}{l} The support ring was driven deeper into the support ring, \\ and the support ring deformation increased. \\ \end{tabular} & High \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of the test result. Figure 11: Effect of the material properties at high velocity (fastener unstable): (**a**) normal and (**b**) high velocity. BwBMFOYrRWY, Figure 10 at [[https://youtu.be/eNK05-bXXaw](https://youtu.be/eNK05-bXXaw)]([https://youtu.be/eNK05-bXXaw](https://youtu.be/eNK05-bXXaw)), and Figure 11 at [[https://youtu.be/dHHzdtEAn0c](https://youtu.be/dHHzdtEAn0c)]([https://youtu.be/dHHzdtEAn0c](https://youtu.be/dHHzdtEAn0c)).