Ale simulation of chip formation in orthogonal metal cutting process

Mohammad R. Movahhedy
This thesis deals with the application of the Arbitrary Lagrangian-Eulerian (ALE) finite element analysis in simulation of chip formation in orthogonal metal cutting process. A critical review of the literature in this field shows that due to the very complex set of conditions present in a cutting process, the application of conventional Lagrangian and Eulerian methods for this problem is inefficient and entails numerical difficulties. In particular, the pertinent problems in the node
more » ... technique or the remeshing approach are discussed. In contrast, the adaptivity of the mesh in an ALE analysis provides the possibility of combining the strengths of both Lagrangian and Eulerian methods in a single analysis. In this approach, the chip formation occurs as a result of plastic flow of the work material around the tool edge on the one hand, and unconstrained flow of the material on free surfaces of the chip, on the other. Due to high deformation speed, strain rate and temperature play a significant role in the chip formation process. In this work, the ALE formulation originally proposed by Wang and Gadala [72] is extended to include rate and thermal effects. A heat transfer module is included that updates the temperature field in the cutting zone at each step of the analysis. Contact algorithms are developed which are able to detect emerging contact conditions and apply contact constraints at interfaces between flexible-flexible or rigid-flexible pairs. An efficient ALE mesh motion is designed that prevents element distortion in the deformation zone and at the same time facilitates the evolution of the chip size at free boundaries. Furthermore, General guidelines for designing a mesh motion strategy are presented, an algorithm for mesh sliding on free boundaries is introduced, and transfinite and isoparametric mapping techniques are adopted for moving the mesh in the interior of the body, so that the mesh remains optimal throughout the analysis The large deformation, rate-dependent, the [...]
doi:10.14288/1.0089713 fatcat:xlns4nhmqfazxbpcjtbp5jxeii