The size-dependent frictionless contact of piezoelectric materials

According to the couple-stress theory, the size-dependent frictionless contact problem between a transversely isotropic piezoelectric half-plane and a rigid conducting or insulating punch is examined in this paper. With the purpose of describing size effect appearing in material microstructures, the couple-stress theory introduces the characteristic length parameter in the constitutive equations. Using Fourier transform method, frictionless contact problems of flat and cylindrical punches are simplified to Cauchy singular integral equations. In order to determine the electric charge density and normal pressure, these equations are numerically solved by trans-forming into algebraic ones. The influences of size parameter and total electric charge on the electric charge density, in-plane electric displacement, in-plane stress, and contact pressure are predicted. Results for the surface electromechanical fields forecasted by the couple-stress theory depart significantly from the classical results.