STATIC RESPONSE OF A SYMMETRIC SPHERE OF FUNCTIONALLY GRADED PIEZOELECTRIC/PIEZOMAGNETIC MATERIALS

A sphere-symmetric problem dealing with a hollow, radially-polarized, piezoelectric/piezomagnetic sphere made of functionally graded (FG) materials is analyzed. Assuming the material properties of the sphere follow a power-law distribution, a closed form solution is derived in spherical coordinates. Numerical results are calculated for a hollow FG piezoelectric/piezomagnetic sphere with an inner surface of BaTiO₃-CoFeO₄ composite, and the distribution of the radial and circumferential stresses as well as the electric potential and magnetic potential are presented graphically under mechanical, electric and magnetic stimuli, respectively. The results indicate that the gradient index strongly affects the stress distribution, electrical, and magnetic response.