Evaluation of the Energy Harvestable from an Airless Tire Equipped with Piezoelectric Bimorphs on the Lamellar Spokes

Abstract

In this work, one evaluates the electrical power generated by an airless tire equipped with piezoelectric bimorphs on both lateral surfaces of the radially distributed lamellar spokes. Such sheet-like spokes are hinged both toward the wheel drum at the inner annular band, and toward the wheel tread at the outer annular band. Since the hinged spokes are able to transmit tension forces but unable to transmit compression forces, bending and buckling of the spokes occur in the region of contact between the tire and the road. Models for the rolling friction of the airless tire, for the bending and buckling deformation of the spokes, and for the electrical power generated by the airless tire are suggested. Variation of the curvature radii and bending deformations for the spokes in the region of contact with the road are illustrated for various values of the rolling friction coefficient and spoke length. Then, variation of the generated electrical power versus the length of contact is obtained for various travel speeds of the vehicle. One observes that the generated electrical power increases at augmentation of the rolling friction coefficient, spoke length and travel speed. Although the obtained electrical power for the proposed harvesting system is relatively modest, it is not depending on the road roughness, i.e. harvesting becomes possible even on smooth roads, such as highway surfaces.