Development and validation of a self-heating model for thick, mixed angle ply composite shafts under rotating bending load

A new analytical model is developed for predicting self-heating in a thick, multilayered, composite shaft spinning in misaligned conditions. The model incorporates a generalized fractional derivative viscoelastic constitutive law for a unidirectionally reinforced lamina, a three-dimensional stress analysis for a shaft loaded in cyclic bending, a strain energy based heat generation model, and a heat transfer model for a spinning shaft. Surface temperature predictions according to the new model are validated with comparisons to finite element analyses and experiments. The new model suggests that shafts can be designed to run cooler when plies generating the most heat are located on the outer surface, where convective cooling is most effective. The novel contributions of this research are the incorporation of multiple helical ply angles into the model and the viscoelastic characterization of a new type of flexible matrix composite material.