Hello,
  I did some works on simulating a piezo injector some months ago by both ANSYS
and Coventor.  As for pzt properties,u can refer the Coventor orANSYS's tutorial
that gives detail description.
  Or u can visit:
  http://www.efunda.com/materials/piezo/material_data/matdata_output.cfm?Materia
l_ID=PZT-5A
   Good luck!
Sean