# Different Configurations of the Non-Minimal Prismatic Tensegrities
## 3 Verification  
### Comparison to Different Solution  
Here, a comparative analysis on the reconfiguration from [61] and prestressing based on the method presented here is performed. In [61] a quarter prism is reconfigured into a non-minimal one. The reconfiguration involves three steps: (1) prestressing the minimal quarterx, (2) attaching additional cables and (3) afterwards shortening them. The initial dimensions of the prestressed module were set as \(h_{g}\) = 10 m, \(r_{g}\) = 5 m, \(b_{g}\) = 13.615 m, \(l_{g}\) = 7.071 m, \(s_{g}\) = 10.708 m and \(\alpha\) = 45\({}^{\circ}\), and the forces were \(N_{1}\) = 2798 N, \(N_{\text{b}}\)= \(-\)7621.3 N and \(N_{\text{s}}\) = 7621.3 N. Afterwards the additional cables were mounted with the length of \(a_{\text{g}}\) = 10.708 m and \(N_{\text{a}}\) = 0 N. The prestressing begins by shortening the additional cables, i.e., \(a_{\text{n}}\) < \(a_{\text{g}}\). The material properties for cables are \(EA_{cab}=6.283\cdot 10^{7}\) N and for struts \(EA_{str}=1.571\cdot 10^{9}\) N. The procedure of the prestressing presented in this paper is different; i.e., the quarterx is in its non-minimal form from the beginning and the internal forces at this point are zero. Therefore, it is expected that some differences in the results of this comparative analysis will occur.  
The results are presented in Table 1, where values given in brackets are from [61] for comparison. The graphical results are presented in Figure 9, where thick lines denote compressed members (struts), and thin lines denote tensioned members (cables). Moreover, the member, which is the cause of the prestress, is denoted in red if it is a bar and in blue if it is a cable.  
The results are comparable; i.e., the differences in the angle of rotation, radius and height are not large, considering the fact that the reconfigured quarterx had initial forces at the beginning, as well as that these are rather different procedures of prestressing. Again, the procedure of the reconfiguration may be understood as external loading, whereas here internal forces occur only due to the changes in member group lengths. Unfortunately, there are not many more examples in the literature to be considered.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Prestress level**} & \(c_{\text{a}}\) = 0.9440 & \(c_{\text{a}}\) = 0.9070 & \(c_{\text{a}}\) = 0.8130 & \(c_{\text{a}}\) = 0.5369 * \\  & (\(e\)/\(l_{0}\) = 0.056) & (\(e\)/\(l_{0}\) = 0.093) & (\(e\)/\(l_{0}\) = 0.187) & (\(e\)/\(l_{0}\) = 0.4632) \\ \hline \multicolumn{4}{c}{Additional cables’ natural length (m)} & 10.108 & 9.712 & 8.706 & 5.749 \\ \hline \multicolumn{4}{c}{Prestressed configuration (no index)} \\ \hline angle \(\theta\) (deg) & 10.54 (10.67) & 17.07 (17.66) & 29.58 (31.01) & 45.00 (45) * \\ \hline radius (m) & 5.01 (5.01) & 5.03 (5.03) & 5.13 (5.16) & 5.66 (5.78) \\ \hline height (m) & 9.68 (9.67) & 9.47 (9.46) & 8.99 (8.92) & 7.10 (6.91) \\ \hline \hline \end{tabular}  
* The angle of 45 deg was obtained in [61] for \(e\)/\(l_{0}\) = 0.486, whereas here for \(e\)/\(l_{0}\) = 0.4632.  
\end{table}
Table 1: Comparative results on the non-minimal quarterx prism.