## 2 Description of the Systems Under Investigation and Experimental Setups
[13] have shown that accelerometers, in fact, do have an influence on the system being tested. Because of this, accelerometers were taken into account when performing computational simulations. Simulated cases both with and without accelerometers were considered to determine the influence that they might have on each BARC system. Table 1 shows the results of the simulations considering cases without accelerometers. It should be noted that the figures in each mode are exaggerated in the simulation and are not what is expected to happen during experimentation. Additional animations are provided in a Supplementary File. Figure 2.2 Random vibration and harmonic vibration testing setup utilizing a slip-table setup for testing of the BARC system. Comparing systems with cuts to one another, there seems to be little to no difference in the mode shapes. But, comparing the cut systems to the no-cut system, more differences can be seen. Mode 2 in the cut systems shows a lot of movement, primarily in the box assembly. This movement is due to the coupling between the removable component and box assembly in the presence of the central cut. Mode 2 of the no-cut system shows more movement in the removable component. Other mode shapes, except mode 4, have similar motions to the cut system, but the no-cut system lacks the flexibility the other systems can reach because it has no cut. Mode 4 of the no-cut system most closely resembles mode 6 of the cut systems, and hence, a switching of modes is obtained due to the effects the central cut has on the coupling between the removable component and the box assembly. These results show the importance the cut has on the system and how having no cut alters the system dramatically. Table 2 shows the mode shapes of the BARC systems under investigation with accelerometers present. Again, like the no-accelerometer cases, little to no difference in mode shapes can be seen when comparing the cut systems. This again shows how little the actual width of the cut influences the mode shapes of the system. But, again, comparing the cut systems to the no-cut system, it can be observed how the mode shapes change,  
\begin{table}
\begin{tabular}{c  
reiterating the effect the cut has on the system as a whole due to the coupling between the box assembly and the removable component in the presence of the central-cut width. Comparing Table 1 to Table 2, the effects of the accelerometer can be observed visually. But, when comparing the tables, little to no influence on the mode shapes can be seen. This shows that the accelerometers do not greatly affect the mode shapes of the BARC systems, if at all. After comparing the mode shapes, an analysis of the natural frequencies found through FEA took place. The goal was to determine whether the accelerometers influence the natural frequencies due to the additional mass. The previous literature has shown that the accelerometers do have a notable influence on the system and should not be left out of simulations [13]. Once again, both without- and with-accelerometer cases were considered. In addition to the physical systems being examined, 0.375\({}^{\prime\prime}\) cut and 0.125\({}^{\prime\prime}\) cut cases were explored computationally to help determine trends in the data as well. The natural frequencies found through FEA simulations both without and with accelerometers are presented in Figure 2.3 First, focusing on the no-accelerometer results, it can be noticed that as the central-cut width decreases from the 0.5\({}^{\prime\prime}\) cut case to the 0.1\({}^{\prime\prime}\) cut case, the natural frequencies found in the system decrease as well. This trend is true across all systems with a cut for each mode. Additionally, the no-cut case is shown to have \begin{table}
\begin{tabular}{c c c c c} \hline  & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mode shapes of BARC systems in the presence of accelerometers. the highest natural frequencies among all systems.