Analysis of maximum radial stress location of composite energy storage flywheel rotor

The relatively low radial tensile strength of a composite circumferential wound flywheel rotor is a crucial factor to restrict the maximum allowable rotation speed and energy storage capability of the flywheel system. In this paper, based on plane stress assumption, the stress analysis of the anisotropic flywheel rotor under the high-speed rotation was performed firstly, and the radial and circumferential stress distributions of the flywheel rotor were obtained. Then, the maximum radial stress location equation was derived by extreme point method and calculated by Newton iteration method. Finally, the effects of the anisotropy degree of the flywheel rotor material, the ratio of inner and outer radii and the rotation speed on the maximum radial stress location were systematically studied. Results provide a valuable reference for the designing of a high-performance composite flywheel rotor.