Simulation of surface grinding
Abstract
Modeling of surface grinding is essential for predicting the high transient temperatures that are generated along the wheel-workpiece interface as well as in the workpiece subsurface because of frictional heating and localized plastic deformation. These contribute to formation of residual stresses as well as workpiece burn. Often when thermal effects dominate, the residual stresses on ground surfaces are tensile in nature. This can lead to microcracking of the surface. If the process of material removal is not considered, surface grinding can essentially be considered as the application of moving pressure and heat flux distributions to the surface of a semi-infinite solid. An efficient finite element procedure has been developed to model moving pressure and heat flux distributions. The thermal load during grinding is modeled as a uniformly or triangularly distributed, 2-D heat source moving across the surface of a half-space, which is insulated or subjected to convective cooling. Grinding of elastic and elastic-plastic workpiece materials are simulated. An analytical solution is formulated for calculating the surface and sub-surface temperatures and stresses produced by a uniform heat source moving across the surface of an elastic half-space which is being subjected to surface cooling. In an elastic-plastic workpiece material with kinematic hardening, an analytical solution is obtained for the residual stress distributions due to thermal load by using an operator split technique. It is found to be in agreement with the elastic-plastic finite element analysis and results in a substantial savings in computational time when compared to the finite element analysis. Next, the moving pressure distribution arising because of the deformation between wheel and workpiece due to the application of a normal force during grinding is considered. Analytical as well as finite element simulations are carried out to predict the residual stresses in an elastic-plastic material under moving load.
Degree
Ph.D.
Advisors
Yang, Purdue University.
Subject Area
Mechanical engineering
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