An optimal control approach to the design of stacked‐ply composite flywheels

This paper presents a novel approach to the design of composite flywheels. Specifically, the paper determines the optimal orientation of fibers in a stacked ply composite disk arrangement. The equations of equilibrium represent the state equations for the system. Classical lamination theory is used to develop the constitutive relations for the composite disk. This allows the orientation of the fibers in the reinforcement ply to be treated as the control variable for the problem. The Tsai‐Wu criterion, which is used to predict failure of the flywheel, is taken as the performance index. Solutions to the optimal control problem yield disk designs that provide energy densities that are 13 percent greater than a benchmark design.