Finite element analyses have been performed on the representative volume element of piezoelectric elements with interdigitated electrodes (IDE). In these investigations the change of the piezoelectric material properties during polarization has been considered prior to additional service loads, e.g. mechanical loading. The numerical results obtained with a specially coded finite element routine are compared with a reference model given by the so called uniform field model. The model indicates stress concentrations at the tip of the finger electrode, which have been validated by experimental results. The modeling approach presented allows for a better understanding of the overall effects in piezoelectric materials with IDE.