Simulation of deep and pendular grinding processes
This project aims to quantitatively predict the residual stresses after grinding processes by means of FE-modeling and simulation.
Grinding often is placed at the end of the manufacturing chain in a wide variety of applications. This renders the grinding a decisive contribution to the component properties in the surface zone. Due to the thermomechanical stress collective in the grinding process, thermal overloading in the material can occur. This can lead to undesirable changes in surface zone properties, such as tensile residual stresses and/or formation of untempered brittle martensite. The wear resistance of ground components essentially depends on the surface zone microstructure, the surface quality as well as the residual stresses. A large number of components, which are manufactured by grinding, are dynamically stressed during use. Residual stresses in particular influence the fatigue resistance, whereby compressive stresses contribute to an increase in fatigue strength and can thus be classified as positive. The service life of a component is therefore decisively dependent on the residual stresses in the component surface zone.
An ICME-type simulation approach was developed to quantitatively predict the residual stress evolution during grinding. Thermomechanical and metallurgical effects due to the stress collective in the surface zone are simulated by means of Finite Element Method in Abaqus. The thermomechanical load collective and the overall material response are modeled in a comprehensive Fortran code taking into account the interaction of effects arising on micro- and macroscopic scales. The heat flux and pressure exposed to the surface zone during grinding are modeled according to the grinding wheel and coolant characteristics as well as further process parameters. The material model (FORTRAN code) included phase transformations, transformation plasticity and phase/temperature dependent material properties. Boundary conditions and the moving heat and pressure source on the surface are set in Abaqus and the FORTRAN code is linked to Abaqus as a user subroutine. The final output of the simulation is the microstructure, yield strength and the residual stress state of the surface zone.
Institute for Materials Applications in Mechanical Engineering IWM,
RWTH Aachen University
Laboratory for Machine Tools and Production Engineering WZL,
RWTH Aachen University
- Duscha, M., Klocke, F., d’Entremont, A., Linke, B., Wegner, H.: Investigation of Temperatures and Residual Stresses in Speed Stroke Grinding via FEA Simulation and Practical Tests. In: Tagungsband zur Manufacturing System. 5. Jg., 2010, Nr. 3, S. 143-148
- Duscha, M.; Eser, A.; Klocke, F.; Broeckmann, C.; Bezold, A.: Phasenumwandlung durch Schleifprozesse. Modellierung und Simulation. In: wt Werkstattstechnik. 101. Jg., 2011, Nr. 6, 2011, S. 390‑397
- Duscha, M.: Beschreibung des Eigenspannungszustandes beim Pendel- und Schnellhubschleifen, Dissertation RWTH Aachen Universität, 2014