Numerical homogenization and simulation of a lamination stack

Parts of electric motors and transformers are composed of sheet-layered lamination stacks, which heavily influence the mechanical properties of such devices. Especially the interaction of individual sheets by direct contact or the presence of bonding varnish may cause a nonlinear deformation behavior such that these effects have to be included in a FE-simulation. Here, homogenization techniques are presented to ensure computational efficiency by avoiding a full numerical simulation with every single sheet and to cover simultaneously the real physical behavior by identifying a linearized transversely isotropic surrogate material model. During this homogenization process, the interlayer between two sheets is incorporated by Zero-Thickness elements.