# Research on High-Speed Vibration and Structure Optimization of Multiwire Sawing Machine
## 3 Results
### Experimental Results  
Finally, after post-processing the test data, the maximum amplitudes of each part of the machine tool at different line speeds were obtained, as shown in Figure 10.  
Compared with the simulation measurements, the experimental measurements of the bottom bracket and subframe are significantly larger. The reason for this is that the bottom bracket was set to fixed support in the finite element simulation calculation, which limits the displacement of the bottom bracket to some extent. The boundary conditions of the subframe winding wheel motor are simplified, resulting in the excitation force on the subframe being smaller than the actual one, so the calculated amplitude value of the bottom bracket and subframe is small, which also leads to the amplitude of the other components being smaller than the test measurement. The above settings and processing of the bottom bracket and subframe make the finite element dynamics simulations easy to converge and calculate the results for.  
Figure 10: Test measurement results.  
Figure 9: Sensor arrangement site plan.  
To ensure the sawing stability of a multi-wire sawing machine, the most important part is the main frame. The main frame is located above a cloth feed platform, and the winding diamond wire saw slot wheel is located in the main frame part. If the amplitude of the main frame is large, then the slicing quality is relatively poor. Therefore, to describe the sawing stability of the multi-wire sawing machine more accurately, the amplitude calculation accuracy of the main frame is the main measurement of the validity and accuracy of the simulation.  
In comparison, the amplitudes of the test frame and electric control cabinet are basically consistent with the simulation results. Considering the simplified simulation model process, the amplitude variation trend of the finite element calculation is the same as that of the field test, and the error is smaller; both are within 11.46%. When the line speed is 1800 m/min, the experimental and simulation results show that the amplitude is about 100 \(\upmu\)m. Therefore, the simulation can accurately describe the variation in amplitude with linear velocity, the error between the electronic control cabinet and the main frame under different line speeds is shown in Figure 11.  
The above analysis shows that a 1200 m/min line speed is the amplitude inflection point of the multi-wire sawing machine, and after this, the amplitude is significantly increased, and the simulation and test results are consistent with the trend of amplitude changes. These are also consistent with those in the research on industrial field use conditions. In this research, the machine site generally uses a line speed of 1200 m/min and a higher line speed for slicing; its surface quality is also reduced, and it cannot meet the production requirements.  
It is determined that the abovementioned finite element simulation calculation has a certain validity and accuracy, which can provide a reference basis for the subsequent structural optimization. Therefore, the next structural optimization is carried out to maintain good operational stability even at higher line speeds.