For conventional material models like Yld2000-2d or BBC05 the equi-biaxial yield strength is required for the parameter identification. In this context, a commonly used test setup is the hydraulic bulge test. However, an inaccuracy in the characterization of the initial yield strength is present in the hydraulic bulge test. Due to the evaluation of the resulting curvature of the specimen, that is nearly infinite at the onset of yielding, the calculated stress can significant vary. Another proposed test setup for the characterization of the equi-biaxial stress state is the layer compression test. Here, the onset of yielding can be characterized with sufficient accuracy. The disadvantage in this test is the friction between stack and tool that leads to an overestimation of the flow curve. Thus, robust and experimental based friction compensation should be used, to gain a comparable hardening behaviour as in the hydraulic bulge test. In this contribution, the friction in the layer compression test is compensated by characterization of the tribological conditions. Thus, the tribological system consisting of workpiece surface, tool surface and lubricant is characterized using pin extrusion tests. The friction is analysed for the two steel grades DC06 and DP600 and the aluminium AA5182. With the identified friction factors, the measured testing force in the layer compression test is reduced by the portion of friction. For verification, hydraulic bulge tests, which are approximately friction free, are performed and compared with the resulting flow curves of the layer compression tests. Results confirm, that a friction compensation of the layer compression tests lead to a significant improvement of the resulting material parameters in comparison to the hydraulic bulge tests. Additional, a new method for the friction factor characterization is presented that uses in the stress difference of flow curves characterized in hydraulic bulge tests and layer compression tests.

对于常规材料模型（例如Yld2000-2d或BBC05），需要等双轴屈服强度才能进行参数识别。在这种情况下，常用的测试设置是液压凸起测试。但是，在液压膨胀试验中，初始屈服强度的表征不准确。由于评估了样品的最终曲率，即在屈服开始时几乎是无限的，因此计算出的应力可能会发生显着变化。用于表征等双轴应力状态的另一种建议的测试设置是层压缩测试。在此，可以足够准确地表征屈服的开始。该测试的缺点是烟囱和工具之间的摩擦会导致流量曲线的高估。从而，应该使用基于实验的稳健和摩擦补偿，以获得与水力膨胀试验相当的硬化性能。通过这种贡献，通过摩擦学条件的表征来补偿层压缩测试中的摩擦。因此，使用销钉挤压试验对由工件表面，工具表面和润滑剂组成的摩擦系统进行了表征。分析了两种钢种DC06和DP600以及铝AA5182的摩擦。利用确定的摩擦系数，在层压缩测试中测得的测试力会减小一部分摩擦力。为了进行验证，进行了几乎没有摩擦的液压凸起测试，并将其与层压缩测试的流动曲线进行了比较。结果证实，与水力膨胀试验相比，层压缩试验的摩擦补偿可​​显着改善所得材料参数。另外，提出了一种新的表征摩擦系数的方法，该方法用于在液压膨胀试验和层压缩试验中表征的流动曲线的应力差。