Piezoelectric effect does not contribute in thermal drilling of quartz bearing rocks

This paper presents a numerical study on a possible piezoelectric effect in thermal drilling of Quartz bearing rocks. For this end, the governing piezoelectro-thermo-mechanical problem is solved with the finite element method. The granitic rock material, consisting of Quartz, Feldspar and Biotite minerals, is taken as linear elastic but heterogeneous and anisotropic. Temperature dependence of material properties is neglected. The simulation demonstrates that the secondary stresses arising from converse piezoelectric effect are three orders of magnitude smaller than the primary thermal stresses, which means that the piezoelectric effect is negligible.