Research On Rotor Assembly Balancing And Dynamic Balancing Methods Based On Multi-objective Optimization

For complex rotating machinery such as aircraft engines,the rotor system often operates under variable speed and supercritical operating conditions,and multiple vibration modes of the rotor are excited.Relying solely on a single speed balance method cannot meet the needs of reducing rotor vibration within a wide operating speed range of aircraft engine rotors.In addition,the assembly of the multi-stage disc structure rotor in the engine takes a long time and is prone to wear,and the residual imbalance of each stage of the wheel disc during assembly is not properly combined,which can easily cause imbalanced vibration faults in the rotor system.The traditional cross reverse assembly method cannot effectively solve this problem.Therefore,studying rotor assembly methods based on multi-objective optimization theory and balancing optimization methods considering multi speed states is of great significance for achieving low vibration and wide operating speed range operation of aircraft engine rotors.In response to the above issues,this article mainly conducts the following research work:(1)A dual screening method for selecting the mating plane of a multi disc rotor system was proposed,taking into account the balancing effect and limiting the counterweight.The first screening aims to achieve the overall balance effect of the rotor system.By comparing the simulation dynamic balance effects of different matching plane selection schemes,the solution set with better balance effect is selected.The second screening involves screening the required weights for different schemes to select the scheme that meets the weight requirements.Finally,by comparing the balance effect coefficients of different schemes,the optimal balance plane selection scheme with better balance effect and smaller balance weight is found.(2)Completed simulation and experimental research on high-speed dynamic balance of a multi disk rotor system considering multi speed states.On the multi disk rotor system test bench,the dual screening matching plane selection method and the dual optimization balance method of the rotor system considering multi speed states were used to simulate and experimentally verify the high-speed dynamic balance of the multi disk rotor system.The results indicate that the suppression effect of rotor vibration caused by imbalance in variable speed operation is significant,which can provide technical support for on-site high-speed dynamic balancing of multi disk rotor systems in variable speed operation.(3)A multi-objective optimization based virtual assembly balance method for multi-stage disc rotors was proposed,and a multi-objective optimization software for virtual assembly balance of rotors was developed.A rotor dynamics model was established based on a multi-stage disc rotor experimental platform,and virtual assembly was carried out using a simulation model with known residual unbalance of each stage disc and original rotor vibration.Taking the residual vibration of each measuring point of the rotor,as well as the overall unbalanced force and moment of the rotor as the optimization objective,the multiple optimization algorithm is used to find the optimization scheme for the assembly angle of each level of disc.Experimental verification was conducted on a three disk rotor system experimental platform,and the results showed that using this method can reduce the vibration of the rotor over a wide range of rotational speeds.We have developed a multi-objective optimization software for virtual assembly and balancing of rotors,providing methods and technical support for assembly and balancing of multi-stage disk structures in aircraft engines.