Contact Problem Of Piezoelectric Materials: Resolved

Piezoelectric materials, due to the characteristic direct-converse piezoelectric effects, have been wildly used in aerospace, mechanical, shipbuilding, medicine, civil engineering, etc. and have received considerable academic attention. Indentation technique, as a fast and efficient technique for measuring the elastic and elastoplastic properties of conventional materials, has also been explored to evaluate the mechanical and electrical properties of piezoelectric materials. As the basis of the indentation technique for piezoelectric materials, the contact mechanics analysis of piezoelectric materials contacting with various indenters has always been of great theoretical importance.This paper concerns the contact between an axisymmetric rigid indenter and a transversely isotropic piezoelectric half-space. It is found that there may be two different treatments regarding the stress singularity at the contact edge. and the difference leads to apparently different formulae of the contact radius. Their effects on the relation between the applied load and the indentation depth as well as the relation between the applied load and the contact radius are studied, and numerical examples are considered for the illustration purpose. Based on the relations between the total force or total electric charge and the indentation depth and electric potential, the sensitivity analysis with respect to material constants are carried out and the effects of two different treatments are discussed through numerical examples.Experiment study of indentation on piezoelectric material by rigid spherical indenter is performed. It is shown that when the indentation coincides with the polarization direction of the piezoelectric material, the electric potential prescribed on the conductive indenter will reduce the indentation depth. This agrees with the theoretical prediction.