Advanced material models are better and better suited to describe relevant aspects of deformation and fracture of technical materials during production and operation. Established procedures of materials testing do often not allow for the determination of the parameters for the new models which are getting more and more complex. Therefore, the reasonable application of novel material models requires the development of new suitable experimental methods for the determination of the necessary material properties. The new test rig and specimen geometry developed at IWM for the determination of cyclic stress - strain curves for sheet materials is one example for this.