Numerical modeling of the thermo-mechanical contact in grinding

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During the grinding process mechanical and thermal loads occur which have a significant influence on the process result. They can lead to changes in the material structure and thus the residual stress state in the external zone of the workpiece, which can adversely affect the subsequent use behavior of the components. In addition, the grinding wheel wear is decisively determined by the forces acting on the abrasive grains. In the machine tool, the process forces during processing affect the elastic displacement of the machine structure. Furthermore, the heat flows also affect the thermo-elastic displacement of the machine structure. Both displacements result in variations in the generated workpiece geometry. Accordingly, in the past, a variety of studies on the analysis of the thermo-mechanical processes in the interaction of grains and the workpiece have been conducted. These can be divided into experimental and simulative studies based on numerical models. Compared to experimental studies in numerical studies the processes and state variables can be determined in higher spatial and temporal resolutions and in particular at each position. In addition, the numerical models allow factors independently to vary and to analyze even if this is not possible in reality. However, a sufficiently accurate representation of reality in the numerical models is a major challenge. Furthermore, experimental studies are also needed in numerical models in order to verify the developed models. Existing numerical models on thermo-mechanical contact of abrasive grains and workpiece are not close enough to reality. In particular the influences of grain shape on the contact conditions are not sufficiently accurate. Therefore, the overall objective of the project is to develop a numerical model for the grain-workpiece interaction in the grinding process, which includes the thermo-mechanical contact conditions sufficiently accurate in order to explore the effect interactions of the contact between grain and workpiece. Furthermore, the influences of the process parameters, in particular of grain shape, on the thermo-mechanical stress should be included. For this purpose, a thermo-mechanical finite element model of the single grain engagement for determining the process forces and heat flows will be developed. The model is verified by experimental single grain cutting tests using the forces and temperatures that occur. After verification of the model, the influence of the process parameters, in particular the grain shape, on the thermo-mechanical loads will be determined systematically and the effect relationships will be explained.