Numerical model development and cutting force analysis for high-speed blanking of 22MnB5

High-speed blanking (HSB) is an advanced cutting process particularly suitable for high-strength steels. Accurate and physically realistic simulation of this process can help to obtain basic understanding of the process mechanisms, but it is challenging due to the very high strain rates, the required thermo-mechanical coupling, and the necessity of representing the elastic characteristics and dynamic behaviour of the tools in the numerical model. Model validation is an added challenge due to the difficulty in accessing the key parameters from the highly dynamic process. In this study, we demonstrate the key aspects of the deforming material and the tool components to be accounted for in the numerical model, as well as the measurement of relevant process variables that can be used to build and validate a realistic process simulation. The validated simulations support interpretation of the experimental results with respect to measured cutting-force curves for two different tools. To describe the deformation behaviour of 22MnB5 under high-speed blanking conditions, the constitutive parameters of the Modified Johnson-Cook model are determined by inverse optimization in LS-OPT for strain rates of up to 3500 s-1. Tensile tests and Split Hopkinson Pressure Bar tests provided the experimental reference for model calibration. For the subsequent HSB process simulation, a three-dimensional LS-DYNA model was built, considering all tool components relevant to the load transmission path. All of these components were modelled as elastic bodies to account for the actual dynamic compliance of the system, which is essential for reproducing the measured time-dependent force. Good agreement between simulated and measured force–time histories demonstrates that accounting for elastic tool deformation in the 3D model is essential for realistic force prediction.