Some aspects of designing multirim composite flywheels

Approximate volutions are given for stresses in a flexible cylindrical interlayer connecting concentric, rigid, cylindrical rims subjected to three loading cases: (i) rotation about the axis of symmetry; (ii) in-plane translation of the rims relative to each other; (in) out-of-plane rotation of the rims relative to each other. The solutions are important for the multiple filament-wound composite rims used in energy storage flywheels, where the elastomeric interlayer idea has been proposed as a means of preventing high radial tensile stresses, which would otherwise break down the rims at less than optimal speeds. The compliances associated with the second and third loading cases are also given, establishing a simple means of analysis of the critical vibration frequencies of multirim flywheel rotors.