## 5 Results and Discussion  
Testing of series 1 and series 2 specimens was carried out as described in Section 3. We have not shown the raw data due to its high volume, including around one thousand points per specimen. In this section, we will discuss the method used to convert the data into useful information. Our objective in the study is to determine the compressive strength of the structures, for which the load required to produce 13% deformation in the height of the test specimen, is applied through a testing machine (Tinius Olsen). Once the data is received from the testing machine, it is imported to an excel sheet to record the amount of load and the subsequent deformation in the test specimen. The recorded data is used to determine the compressive strength and strength to mass ratios are calculated through Equation (1). From the load and subsequent deflection, data is used to calculate the amount of strength exhibited by the specimen against 13% axial deformation. Figure 8a,b provides the graphical representation of the data points. An increasing trend in strength is observed for both 70% and 100% infill density specimens. Figure 8a provides the comparison, which shows that the solid specimen is much stronger, as compared to the specimen having an internal structure with 100% infill density. The performance of specimens with 70% infill density (see Figure 8b) is more valued, as all of the specimen are of greater strength than the solid specimen having a 70% infill density. Figure 8: Graphical representation of the relationship between strength versus vertical shift (**a**) with 100% infill density (**b**) with 70% infill density. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{\(f_{2}\)} & \multirow{2}{*}{\(v\)} & **Average Mass** & \multirow{2}{*}{**Average Compressive Load**} & **Strength/Mass** & **\% Improvement in** \\  & & & **of Specim** & **(\(F_{c}\)) (kN)** & **Ratio (MPa/g)** & **Strength/Mass** \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Cellular \\ Lattice \\ Structure \\ \end{tabular} } & 21 & 0 & 58.4 & 72 & 0.47 & 23.6 \\ \cline{2-6}  & 21 & 0.1 & 61 & 81 & 0.51 & 34.2 \\ \cline{2-6}  & 21 & 0.2 & 61.2 & 80 & 0.5 & 31.5 \\ \cline{2-6}  & 21 & 0.3 & 60.17 & 89 & 0.56 & 47.3 \\ \cline{2-6}  & 21 & 0.4 & 62.72 & 105 & 0.64 & 68.4 \\ \hline Solid Part & - & - & 62.4 & 62 & 0.38 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Second test series results of test specimens with frequency 21 and 70% infill density. Figure 9a,b shows the relationship between specimen mass and vertical shift. Comparison between Figures 8a and 9a show that, for 100% infill density, the strength of specimen mostly follows the same trend, where an increase in mass increases the strength of specimen. It is also observed that, with an increase in the value of vertical shift, the mass and the strength of the specimen mostly increases. The response of the 70% infill density specimen shows better performance, as indicated by Figure 9b. Graphical representation of mass vs vertical shift shows that the masses of specimens with internal structure are equal to, or less than, the mass of solid specimen. A comparison between Figures 8b and 9b reveals that the mass of specimen is not the only factor that contributes towards greater strength, as it can be seen that specimens of equal masses do not perform uniformly and have different values of strength. Figure 10a,b shows the strength to mass ratios versus vertical shift of specimens with 70% and 100% infill density. For 100% infill density specimens, a zigzag trend is observed for specimens with frequency \(f_{1}\) (19), and an increasing trend is observed for specimens with frequency \(f_{2}\) (21). The strength to mass ratio of solid specimens is higher than the values of 100% infill density with internal structure specimens, except for the specimen with frequency 21 and vertical shift 0.4, having the same value of strength to mass ratio. Similar results are observed through the research study of [PERSON] et al.