Analytical analysis of the stent system In order to understand the dynamic characteristics of the stent system, various analytical calculations were performed on the stent system, and the effects of parameters that are difficult to determine were quantified. Firstly, the free modal analysis and constrained modal analysis are carried out on the system consisting of the generator bracket and the compressor bracket. Secondly, the constrained modal analysis is performed on the system consisting of the generator bracket, the compressor bracket and the generator compressor support. The influence of the moment of inertia and centroid position of the generator and compressor was evaluated. Finally, the complete system of the generator bracket, compressor bracket, generator, compressor, generator and compressor support was constrained. On the basis of the above analysis, the state analysis establishes a system model that is most consistent with the actual situation. The actual generator and compressor model is established in the system, and the actual bolt connection relationship between the components is considered. The final finite element model is shown in Figure 4.
Wherein the two bolt connection faces of the generator bracket and the engine body, the two bolt connection faces of the bracket and the generator body and the bolt connection faces of the bracket and the engine body apply a fixed constraint. Modal order mode frequency mode order mode frequency, the third and fourth order natural frequencies are 433.2 Hz and 567.7 Hz, respectively, and these two frequencies correspond to the generator rotation when the engine speed is about 4200 rpm. 3 times the frequency and 4 times the frequency. From the perspective of the mode corresponding to each mode, the lateral vibration of the stent system is mainly dominated, which is quite consistent with the actual vibration. The possible damage locations corresponding to the vibration modes obtained from the vibration mode are also completely consistent with the actual damage conditions. It should be noted that on the one hand, due to the analytic calculation, a lot of simplifications are made to the actual situation, and the results of the analytical calculation and the actual results necessarily have a certain deviation. On the other hand, since the actual experiment is to change the vibration intensity of the system with the engine speed, instead of performing the experimental modal analysis of the system, the experimental conclusions obtained are not accurate modal results. But this does not affect the correctness of the analysis conclusions. In the analysis of this paper, the main factors affecting the analytical analysis results are as follows: (1) the simplification of the actual compressor and generator; (2) the simplification of the actual bolt connection; (3) the neglect of the actual belt preload (4) The error between the theoretical assembly position and the actual assembly position; (5) The simplification of the fixed connection between the generator bracket and the bracket and the engine body.