# Study on Influence of Multi-Parameter Variation of Bladed Disk System on Vibration Characteristics
## 5 Conclusions  
Taking the rotor disk system of aero-engines as the research object, the modal calculation of the rotor disk system was carried out based on the group theory, and the simulated disk vibration mode was represented by the movement of fine sand on the disk. The experimental vibration mode was compared with the finite element calculation results to verify the reliability of finite element analysis. The comparative analysis of the modal of the disk and the bladed disk system, the effect of the change of the quality of a single blade on the bladed disk system's modal frequency, the effect of the increase of the angle of the interaction between double blades on the bladed disk system's modal frequency, and the effect of bladed loss on the modal frequency of the bladed disk system were analyzed, and the following conclusions were drawn.  
1. The modal test results of the disk were basically consistent with the finite element calculation results, which verified the accuracy of the finite element analysis. The vibration shape trends of the bladed disk system and the disk were basically consistent, and the modal frequencies of the bladed disk system were all smaller than the modal frequencies of the disk.
2. When the mass on different parts of a single blade increased, the vibration amplitude corresponding to the addition of the counterweight on the top of the blade increased, and the corresponding vibration frequency was not obvious; the greater the mass of the counterweight at the same position, the slightly smaller modal frequency, the corresponding maximum amplitude increases more obviously.
3. The modal vibration frequency of the double blades at an angle to each other and the counterweight was less than the modal vibration frequency when the counterweight was not added. The mode of the blade was affected by the position of the weighted blade, and the amplitude change had no obvious law.
4. When the bladed disk system vibrated at low frequency, the disk vibration was dominant one, and the blades vibrated with the disk. In a certain frequency range, the disk would not vibrate, and each blade vibrated irregularly. During the working process, use of the blade disk should be avoided in this working area for a long time, otherwise it will lead to fatigue damage of some blades and even damage to the blades.  
Conceptualization, H.P. and T.Z.; methodology, H.P. and Y.W.; software, Y.W.; validation, H.P.; formal analysis, Y.W.; investigation, H.P. and T.Z.; resources, H.P.; data curation, Y.W.; writing--original draft preparation, H.P.; writing--review and editing, Y.W.; visualization, Y.W.; supervision, T.Z.; project administration, H.P. and T.Z.; funding acquisition, H.P. and T.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded the National Natural Science Foundation of China, grant number 51775093, China Postdoctoral Science Foundation, grant number 2019M661125, Doctorate Start Foundation of Liaoning Provincial, grant number 20180540077, Scientific Research Funding Project of Liaoning Education Department, grant number Jl-2003, Science and Technology Program of Shenyang, grant number 20-206-416, Science and Technology Innovation Team Support Program of Shenyang middle-aged and young people, grant number RC190342.  
Not applicable.