# Different Configurations of the Non-Minimal Prismatic Tensegrities
## 5 Discussion  
In general, these systems, depending on the material properties and selected cross-sections, can produce an interesting set of mechanical responses, which could be used in many fields of tensegrity analyses, such as robotics, civil engineering, meta-materials, etc. However, for the sake of this discussion, mainly potential advantages of their usage in civil engineering are discussed.  
The first advantage in terms of the potential usage in civil engineering is the lack of infinitesimal mechanisms. Infinitesimal mechanisms create load paths that have very low mechanical responses and are stabilized by increasing the prestress levels. Increasing the prestress levels requires an increasement of the sizes of the cross-sections. Also, there are no eigenmodes and eigenfrequencies originating from these mechanisms, which are typically the lowest of all modes and frequencies of a particular structure. Another aspect of this change is that increasing the prestress levels also decreases the damping--see for example [77]. Moreover, bars in the _2t_-configurations create a continuous frame (see Figures 11 and 13a,d,e). This is expected to increase the stiffness, yet this needs to be verified quantitatively.  
Figure 13: Prestressed non-minimal pentex configurations–prestressing by (**a**) shortening the cross cables, (**b**) lengthening the bars, (**c**) shortening the horizontal cables, (**d**) shortening the additional members and (**e**) lengthening the additional members. Letters a–e match scenarios 1–5 in Table 4, respectively.  
Another advantage originates from the increased internal space--see the comparison between a minimal triplex and non-minimal triplex (doubled bars) for \(\theta=-15^{\text{o}}\) in Figure 14. As can be seen, the latter possesses a larger inside radius. This enables to consider such module as usable segments of industrial towers or sightseeing towers, where the internal part would enable to lead the infrastructural or communication paths. Please note that the internal part is actually adjustable by changing the values of the \(\theta\) angle.  
In practical applications, a typical issue is the creation of joints. Joints of the Rostock Tower were connecting two bars and four cables in each node. Two bars did originate from connecting the lower and upper segments of two different triplex modules (Figure 2a). Here, in the case of the \(2t\)-configurations, a total of four struts and four cables would need to be connected, which complicates the process. However, in the case of steel designs, a starting point can be achieved by using the standard [78], where such connections are considered for rectangular and circular hollow sections.  
The potential applications in civil engineering are numerous, including towers with cantilever static schemes; small architecture objects or small modern modules of houses; and potentially every type of structure where modern architectural looks are important. Also, in case of deployable structures or soft robotics, an advantage may come from possibility of mounting the additional member with adjustable lengths. This way, changing the lengths of additional members changes the stiffness of the structure and allows it to rotate at a positive or negative angle \(\theta\). However, these matters need to be studied more deeply.