Numerical modeling of the thermo-mechanical contact in grinding

磨削过程中产生的机械载荷和热载荷对磨削效果有重要影响。它们会导致材料结构的变化，从而导致工件外部区域的残余应力状态，从而对部件的后续使用行为产生不利影响。此外，砂轮的磨损决定性地取决于作用在磨粒上的力。在机床中，加工过程中的加工力影响着机床结构的弹性位移。此外，热流还会影响机器结构的热弹性位移。这两种位移都会导致生成工件几何形状的变化。因此，过去对晶粒与工件相互作用的热-机械过程进行了各种分析研究。这些研究可分为基于数值模型的实验研究和模拟研究。与数值研究中的实验研究相比，过程和状态变量可以在更高的空间和时间分辨率下确定，特别是在每个位置。此外，数值模型允许因素独立变化和分析，即使这在现实中是不可能的。然而，在数值模型中充分准确地表示现实是一项重大挑战。此外，还需要在数值模型中进行实验研究，以验证所开发的模型。现有的磨粒与工件热-机械接触数值模型与实际情况不太接近。特别是颗粒形状对接触条件的影响不够精确。因此，该项目的总体目标是建立磨削过程中晶粒与工件相互作用的数值模型，该模型包括足够精确的热-机械接触条件，以探索晶粒与工件之间接触的效应相互作用。此外，还应考虑工艺参数，特别是晶粒形状对热机械应力的影响。为此目的，将开发用于确定过程力和热流的单晶粒接合的热-机械有限元模型。通过单晶粒切削力和切削温度的实验验证了模型的正确性。在对模型进行验证后，将系统地确定工艺参数，特别是晶粒形状对热机械载荷的影响，并解释其影响关系。

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.