A Simplified Analysis of Crack Growth in a Steady State of Piezoelectric Ceramics by the Double Cantilever Beam Model
Mamoru MIZUNO, Yoshinori HONDA and Hiroyuki KATO
Abstract:A simplified analysis of crack growth in a steady state of piezoelectric ceramics was performed by using the double cantilever beam (DCB) model. A constitutive equation of piezoelectric ceramics and a damage evolution equation that have been formulated by the authors were applied to the DCB model. The crack growth in the DCB model was dealt within the framework of the continuum damage mechanics; I.e. damage development in piezoelectric ceramics was described by the evolution equation of a damage variable and the so-called local approach was applied to the analysis. The analysis was intended for crack growth in a steady state for the sake of the simplification and moreover it was simplified by using some assumptions. By using the DCB model, a constant crack growth rate and distribution of stress, strain and damage variable in front of the crack tip under mechanical and electric loads were elucidated and the effects of applied electric field on them were discussed. Furthermore, concentration of electric field around a crack tip was taken into account in the DCB model and the effect of the concentration of electric filed on the crack growth was clarified. Key Words:Piezoelectric ceramics, Crack growth analysis, Continuum damage mechanics, Local approach, Double cantilever beam mode, Crack growth rate