DETC2008-49066 A SECOND GENERATION OF NUMERICAL IMPLEMENTATION OF NONLINEAR PIEZOELECTRIC MODELS IN COMMERCIALLY AVAILABLE TOOLS

ABSTRACT Domain switching based nonlinear behavior is characteristic of relaxor-type piezoelectric material such as PMN-PT single crystals. These materials offer significant device performance improvements over traditional polycrystalline piezoelectric materials such as PZT-5A. The promise of increased performance of these materials has led to work in development of constitutive characterizations so that material behavior under load and material failure mechanisms can be understood and predicted. However, there is a gap between development of such theoretical developments and in workable manifestations available as part of commercial finite element codes for use in device design. In the current work, the authors extend previously documented implementation of a macro-mechanical constitutive model which addresses domain switching, into a commercially available finite element code. A rate dependent version of the constitutive model has been successfully realized and used to reproduce a variety of piezoelectric constitutive behaviors. INTRODUCTION New materials drive the need for new modeling capabilities. There are numerous applications of piezoelectric materials for which linear response is sufficient. Existing codes are also sufficient for these devices. But in order to take advantage of the performance advances promised by new materials more advanced constitutive responses must be incorporated into computational tools. In order to properly use computational design processes for crystal piezoelectric material appropriate tools are needed. In these materials failur