Structural Strength And Modal Analysis Of Composite Flywheel Rotor

With the development of society,energy and environmental protection have been paid more and more attention,and the development of composite materials,permanent magnetic bearings and motor control systems has made the performance of the flywheel energy storage system greatly improved,so as a new energy storage technology with large capacity,high efficiency and zero pollution,it has a very broad application prospect in the field of energy saving and emission reduction.Flywheel rotor as the energy storage component of the system is the core of the whole system,so the analysis and research of flywheel rotor is of great importance.On the basis of reading a lot of literatures,we have studied the research status of flywheel rotor both at home and abroad.By comparing the performance parameters of a variety of latest composite materials and considering the material cost,energy storage density and specific strength,T700/5028 epoxy resin was used as the composite material for making flywheel rim,and aluminum alloy was selected as the hub material.The wheel rim of the design flywheel is 5 layers of ring suit.On the basis of the six hubs,the hub part is optimized,the hub mass is reduced by 10.5%,and the stress concentration problem is improved.The maximum stress can be reduced by 20% under the working condition of 10kr/min.In view of the shortcomings of most of the Tsai-Hill strength criteria used in the analysis of flywheel at present,the innovation of this paper is more suitable for the application of the Tserpes strength criterion of three-dimensional failure analysis to the failure analysis of the composite flywheel,which is beneficial to the accuracy of the analysis results of the flywheel.At present,the stress and modal analysis of the composite flywheel are less related to the initial stress factors of the flywheel,and the initial stress of the flywheel will affect the stiffness matrix of the flywheel.The influence of the flywheelon the overall performance of the flywheel cannot be ignored.In this paper,the initial stresses of five different distribution forms,including uniform distribution,linear increasing,linear decreasing,convex parabola and lower convex parabola,are applied to the flywheel rotor.The stress analysis,modal analysis and the critical speed and the limit speed are carried out for the flywheel with the above initial stress.After comparing and analyzing the calculated data,the results are obtained.The application of certain initial stress to the composite flywheel is beneficial to reducing the maximum stress of the flywheel,improving the overall performance of the flywheel structure,improving the ultimate speed and critical speed of the flywheel,and preventing the occurrence of resonance.According to the effect of the initial stress on the size of the flywheel stress,it is found that the best way to apply the initial stress is reduced from the form of gradient distribution from the inside to the outside,but the distribution mode of the initial stress has no obvious influence on the natural frequency and critical speed of the flywheel.By analyzing the initial stress of flywheel,this paper provides theoretical guidance for future flywheel design.