Investigation of indentation response of bi-directional functionally graded materials

Abstract

Functionally graded materials made of more than two material constituents have been recently introduced in order to control stiffness and contact response. In the present study, effects of bidirectional gradation of the mechanical properties of functionally graded materials, made of more than two distinct material constituents, upon the indentation response are investigated. Utilizing isoparametric graded finite elements formulation to realize the gradation of material properties, the problem is handled in the framework of the mechanics of functional graded materials coupled with contact mechanics to investigate the nonlinearity inherent with indentation problems. The obtained results showed that the bidirectional gradation of the material properties and the indenter radius have significant effects on the indentation response of bidirectional functionally graded materials. Also, it is indicated that the indentation configuration can be effectively controlled by imposing a bidirectional gradation in an elastic material.