## 3 Results and Discussion
### Discussion  
The results of the finite element method in the vibration test experiment determine the natural frequency with three types of specimens. The specimens have a 5 mm thickness and a clamping distance of 100 mm. These are the same for all three types: full square sheets, hole sheets, and V-notch sheets. The natural frequencies obtained from the experiment were compared with the finite element method model results and used to create behavioral predictions and predict the onset of internal damage and fracture in low carbon steel. The motion region was set the same as the test result, as shown in Figure 11. The natural frequency of each sheet metal design was collected from the FE model analysis; the natural frequency is shown in Table 6 and Figure 11, which is a graph and the natural frequency in Hz. The values in Table 3 show that the natural frequency of each sheet metal design is different. The value representing the natural frequency is the natural frequency in modes 1 to 20 for carbon steel sheet metal; when using such values to plot the relationship between mode and natural frequency, the values differ for each shape. Figure 11 shows that in mode 1 to mode 3, the natural frequency values are similar; with similar values, the difference is 5 \(\pm\) 0.45%, and when considering mode 4 to mode 12, it shows that the V- and U-shaped notch patterns have natural frequencies higher than in the notched form and perforated, respectively The resulting difference was 25 \(\pm\) 7.32%. Subsequently, in mode 13 to mode 20, the V- and U-shaped notch patterns showed a marked increase in the natural frequency difference. Moreover, there are also higher values in the unnotched form and perforated, respectively; the resulting difference is 40 \(\pm\) 12.47%. The naturalness of the virgin steel and hole workpieces being displayed consistently has led to the research of [PERSON] et al. (2015), [PERSON] (2016), and [PERSON] et al. (2019), who lead research in structural engineering on the problem of vibration under a loaded object. An example to simulate is sheet metal with three models: a pure sheet metal without holes plate, with designated holes, and a solid metal plate on one side. The model was simulated with modal analysis. Therefore, 20 natural frequencies were recorded. The sample also used low carbon steel material. Several random frequency models prove the deformation of various objects. Many types of sheet metal designs, such as pure sheet metal, used side hole punches, and the work of [PERSON] et al. (2019), who have studied and reported the results of this work, analyzed a series of container ship collisions in the maritime realm to examine the structural phenomena that occur. The finite element method is chosen to resolve the designed collision case. Discussions will be directed toward the selected protection criteria. By testing and comparing the FE model by using an entire rectangular piece to calibrate the actual test results with a calculated value, the FE model methodology from the research report shows that with the result of the calculation with the FE model methodology, the test results can be significantly predicted. Figure 11: _Cont._To measure different types of deformation in a given mode, one must first determine the distance that the workpiece has deformed. Specifically, mode 5 is operated for analysis with random frequencies. Upon examination of Figure 12, it becomes apparent that the deformation is relatively uniform across the workpiece. However, it is worth noting that the pure sheet metal model, without any notches at the corners, experiences the most severe deformation elongation. Furthermore, the center of the workpiece displays a variation in mean value. On the other hand, the perforated sheet metal model, as shown in Figure 12, displays the worst deformation out of all the models. It has the four worst deformation points. This is because deformation intensity is present in almost all parts of this model due to the holes.