Analytical determination of the orthotropic material behavior of stator bars in the range of the end windings

The end windings of generators are excited to vibrations due to electromagnetic forces which can cause severe damage (especially in case of resonance) and noise. To avoid this, it is important to predict the natural frequencies and modes of the end windings with finite elements during the design process. Hence, a material model of the complete stator bar is necessary. This paper shows the development of such a material model. The composite structure of a stator bar is quite complex and makes it impossible to provide a quick calculation of the eigenvalues. That´s the reason for using a suitable, homogeneously, geometry based solid model.