Abstract: On the basis of three different gradient models which are polynomial function，fraction power function and exponent function respectively，we simulated the nonlinear characteristics of distribution of physical properties of the across the thickness of piezoelectric functionally graded material by means of analytic theory and obtained the in-plane stress and out-of-plane displacement by the modified classical lamination theory.

Key words: piezoelectric material, functionally graded material, gradient model, physical properties