## 3 Experimental Details
### Model Experiment
#### 3.2.2 Data Acquisition  
To find out the mechanical excitation of a structure, an external impulse is provided to the machine using a hammer. The hammer comes with a configurable tip made of rubber and an extender weight. The sensitivity configuration is adjusted as shown in Table 7. An accelerometer sensor with 3-axis calibration is used to record the vibration signals at different points. It contains a piezoelectric crystal that generates a proportional force that generates a high-impedance electric charge that is proportional to the applied impulse and acceleration. The sensitivity calibration is given in Table 7. Both of these devices are connected to a SCADAS (Signal Conditioning and Data Acquisition) unit, which is connected to a PC and a computer program, NOVIAN. The SCADAS/Spectrum analyzer comes with a 4-channel input and a single output signal. The signal contains coherence, auto spectrum, time wave form, and frequency response function (FRF). FRF holds the machine response to excited frequency.  
ME'scope analysis software was used to perform post-analysis on the obtained vibration data. Vibration parameters of a vibrating structure can be analyzed and recorded  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **(a)** & & & **(b)** \\ \hline \multirow{2}{*}{Configuration} & Tip & Grey-9912 & Axis & Sensitivity \\ \cline{2-5}  & Extender & none & X & 103.9 mV/g \\ \hline \multirow{2}{*}{Sensitivity at 100 Hz} & mV/N & 0.193 & Y & 104.0 mV/g \\ \hline \multirow{2}{*}{Sensitivity ratio at 100 Hz} & N/g & 53.69 & Z & 104.6 mV/g \\ \hline \hline \end{tabular}
\end{table}
Table 7: Sensitivity configuration: (a) hammer and (b) accelerometer sensor.  
Figure 17: Experimental apparatus.  
with the help of ME'scope, a post-test analysis software tool. Spatial vibration data are also displayed on a 3D model of the structure. This program allows for the visualization of Operating Deflection Shapes (ODSs) and Mode Shapes. A total of 58 points were marked on the structure in order to collect the relevant vibration data. An accelerometer was installed at reference point 8, as stated in Table 8, and an impact hammer was used to apply excitation to each of the 58 points individually. The impact reaction was measured using an accelerometer in terms of frequency response functions (FRFs) at 58 points, using a dynamic signal analyzer. ME'scope software was used to create the structure model, and vibration data from the test setup were loaded into it in the form of FRFs. The FRFs were chosen in an overlay format to guarantee that all FRFs participated in evaluating the structure's modal parameters. Given that the structure is three-dimensional, each FRF data point corresponding to a hitting location on the structure was allocated a degree of freedom (DOF). The imported FRFs supply all of the information required by modal analysis software to predict the behavior of the actual vibrating structure in the mode shape table, which includes the number of modes, natural frequencies, and damping parameters. The vibrations produced during the impact hammer test enveloped the entire machine. The computed model parameters for the structure are listed in Table 8, in which the natural frequencies from the first to the fifth mode shaper were observed sequentially.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Frequency (Hz)** & **Mode Shape** & **Illustrate** \\ \hline
27.3 & & The main mode shape of the first-order mode is the displacement of the tool magazine in the X-direction. \\ \hline \hline \end{tabular}
\end{table}
Table 8: Results of modal experiment.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Frequency (Hz)** & **Mode Shape** & **Illustrate** \\ \hline \hline \end{tabular}
\end{table}
Table 8: _Cont._