On a plane crack in piezoelectric solids

A new analytical solution for a piezoelectric plane with an elliptical void is derived by removing the commonly held assumptions that the void boundar y is impermeable and a void axis is perpendicular to the poling direction. The approach of Lekhnitskii's complex potential functions is used in the de rivation. Applicability of the common practice of reducing a void solution to a crack solution is examined. It is shown that a recently reported solut ion for exact electric boundary conditions is actually the well known solut ion for a permeable crack. A unified formulation for plane cracks containin g air or vacuum is then developed to account for different electric boundar y conditions. Crack closure is taken into consideration in the analysis. Th e influence of electric boundary conditions and crack orientation on fractu re parameters is discussed. (C) 2001 Elsevier Science Ltd. All rights reser ved.