Abstract
In this work one evaluates the energy harvestable from an airless tire equipped with piezoelectric bimorphs on both lateral surfaces of the tire's elastic elements, which can be either lamellar hinged spokes or tread supporting omega springs. Electrical power is obtained due to the cyclical bending or buckling of the piezoelectric bimorphs together with the associated elastic elements in the region of contact with the road. Piezoelectric bimorphs are metallic springs with lateral surfaces coated by a piezoelectric ceramic material. Models for the bending deformation of the spokes and omega springs, as well as for the electrical power generated by the airless tire are suggested. Then, variation of the bending and buckling deformation of the spokes and omega springs on the contact surface with the road is investigated for various values of the rolling friction coefficient and geometrical parameters of the tire. In the end, variation of the generated electrical power versus the travel speed of the vehicle for various geometrical parameters of the tire is clarified. The following main conclusions were inferred: generated electrical power is proportional to the density of the piezoelectric ceramic material, to the mean potential energy of deformation of the bended elastic elements, and to the rolling friction coefficient; it is also proportional to the second power of the global electromechanical constant of the piezoelectric bimorph, and to the third power of the vehicle's traveling velocity.
