# Mechanical Behavior of Hollow Corrugated Sandwich Cylinders Under Inner Pressure Loading
## 6 Conclusions  
Due to the high structural efficiency and growing trend of multifunctional application, the hollow corrugated sandwich cylinder has been widely used in aviation, high-speed trains, packaging, and other fields. In this paper, the mechanical behaviors of the hollow corrugated sandwich cylinder under inner pressure loading were investigated, yielding the following key conclusions:  
1. Concerning the long, hollow sandwich cylinder without column caps, an elastic closed-form solution and the minimum weight design model of the hollow corrugated sandwich cylinder were proposed with the homogenization method.
2. The stress distribution of the hollow corrugated sandwich cylinder with different topological structural parameters was compared and analyzed. It is found that there is an inflection point of the structural efficiency during the increase in the pressure. Notably, the hollow corrugated sandwich cylinder demonstrates a relatively pronounced structural advantage only when subjected to significant internal pressure.
3. The optimal structural efficiency of the hollow corrugated sandwich cylinder is closely related to its topological parameters. With the increase in the topological parameters, including core thickness, inner facesheet thickness, outer facesheet thickness, core thickness, and core inclining angle, both the minimum weight and the limit load increase accordingly, leading to a relative advancement of the inflection point in the structural efficiency curve.
4. The model did not consider the influence of the failure between the core and facesheets, which should be further investigated to improve the accuracy and practicability of the model.  
Conceptualization, L.Z. and R.G.; data curation, L.Z.; formal analysis, L.Z.; funding acquisition, H.Z.; investigation, L.Z. and H.C.; methodology, L.Z.; project administration, R.G.; resources, L.Z. and C.C.; software, L.Z. and J.W.; supervision, R.G.; validation, L.Z., C.C. and Y.Y.; visualization, J.W.; writing--original draft, L.Z.; writing--review and editing, Y.Y. and H.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China, grant number 12102199.  
Not applicable.  
The data that support the findings of this study are available from the corresponding author upon request.  
[PERSON] thanks other members in his group for the support on this research.  
Author [PERSON] was employed by the company Anhui Dongfeng Electromechanical Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & \multicolumn{2}{c}{**Relevance**} \\ \hline Size design variables & \(t_{i}\) & 0.6133 \\ \(t_{o}\) & 0.6087 \\ \(t_{w}\) & 0.5720 \\ \hline \multirow{3}{*}{Shape design variables} & \(h_{c}\) & 0.6954 \\ \(\rho\) & 0.6873 \\ \(f\) & 0.6690 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Relevance of structural parameters based on GRA.