## 3 Results
### Identification of Strain-Rate-Dependant Flow Curves
The yield curves for the subsequent higher strain rates tested, together with the approximated curves, are shown in Figure 10. Obviously, the approximation method used shows good agreement with the experimental data; this is especially noticeable for actual strain rates of 0.08 and 4/s. From an actual strain rate of 60/s, the curve of real values has a wavier shape, which is even more noticeable for an actual strain rate of 180/s because of the high strain rate. However, the approximated values are still close to the experimental data. Numerical Simulation of the Tensile Test and Experimental Validation of Force and Temperature Values  
As mentioned above, the determination of the mean strain rate via Equation (1) provides a good approximation of the strain rate as long as the specimen deformation is uniform. As soon as localization occurs, the strain rate is no longer distributed homogenously in the specimen. It rises quickly in the areas of localization and the local strain rate in the fracture zone is much higher than the analytically calculated nominal and actual values. This can be clearly seen in Figure 11. This figure compares the strain rate courses obtained from the simulation for individual elements near and slightly beyond the fracture zone of the sample for the four considered strain rates. At the beginning of the test, the strain rates are very similar for all elements in the specimen, but with further progress, the curves start to deviate from each other. The strain rate of element 1 that is located in the middle of the specimen rises dramatically, while the strain rates of elements 2 and 3 tend to remain on the same level for some more time and finally decrease. This clearly reflects the localizing of the strain and the strain rate in that region of the specimen, where damage and finally failure of the material can be observed. Therefore, the range of strain-rate-dependent flow curves necessary for realistically modeling damage and failure significantly exceeds the nominal and actual strain rates defined for the test in Section 3.1. For this reason, auxiliary yield curves were additionally approximated using Equation (3). A logarithmic relationship for three different true strain values as a function of strain rate was used as a reference as shown in Figure 12. This allowed an extended material model with strain rate dependence to be used when simulating the LS DYNA uniaxial tensile test. In order to verify the material model, numerically calculated and measured force-displacement curves for actual strain rates of 0.08/s and 60/s were compared (see Figure 13). Up to the maximum stress, the agreement is very good. However, as soon as necking starts, the stress state becomes multiaxial, and the softening is different. This results in a deviation of measured and numerically determined displacement and strain at failure in the range of 10%. Figure 10: Approximated yield curves for actual strain rates of 0.08/s, 4/s, 60/s, and 180/s. Figure 7:0 Comparison of strain rate values for individual elements obtained from process simulations for actual strain rates of 0.08/s (**a**), 60/s (**b**), 180/s (**c**), and 700/s (**d**). Figure 7:1 Logarithmic dependence of strain rate and yield strength for three different degrees of true strain. Figure 7:2 Comparison of experimental force-displacement curves with simulation results for actual strain rates of (**a**) 0.08/s and (**b**) 60/s. For further validation, the temperature reached in the fracture region was recorded in simulation and experiment for actual strain rates from 0.08/s to 700/s. Considering an actual strain rate of 0.08/s as an example, Figure 14 compares the thermal camera data with simulation data for three significant stages of the test process: shortly before fracture, at the moment of fracture, and after complete fracture of the sample. The comparison shows good qualitative and quantitative agreement of simulation and experiment with a deviation of the maximum temperature of less than 7% until the onset of fracture.