Numerical and analytical modeling of orthogonal cutting: The link between local variables and global contact characteristics

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. The response of the tool-chip interface is characterized in the orthogonal cutting process by numerical and analytical means and compared to experimental results. We study the link between local parameters (chip temperature, sliding friction coefficient, tool geometry) and overall friction characteristics depicting the global response of the tool-chip interface. Sticking and sliding contact regimes are described. The overall friction characteristics of the tool are represented by two quantities: (i) the mean friction coefficient qualifies the global response of the tool rake face (tool edge excluded) and (ii) the apparent friction coefficient reflects the overall response of the entire tool face, the effect of the edge radius being included. When sticking contact is dominant the mean friction coefficient is shown to be essentially the ratio of the average shear flow stress along the sticking zone by the average normal stress along the contact zone. The dependence of overall friction characteristics is analyzed with respect to tool geometry and cutting conditions. The differences between mean friction and apparent friction are quantified. It is demonstrated that the evolutions of the apparent and of the mean friction coefficients are essentially controlled by thermal effects. Constitutive relationships are proposed which depict the overall friction characteristics as functions of the maximum chip temperature along the rake face. This approach offers a simple way for describing the effect of cutting conditions on the tool-chip interface response. Finally, the contact length and contact forces are analyzed. Throughout the paper, the consistency between numerical, analytical and experimental results is systematically checked.

Analysis of adiabatic shear banding in orthogonal cutting of Ti alloy

“…The results obtained here in the context of chip segmentation by adiabatic shearing generalize those derived in [2,21] in the context of continuous chip formation Lastly, the correlation of the theoretical results with experimental data was found to be satisfactory.…”

“…The width of cut was 5 mm. We note that, in agreement with [21], the effect of μ is getting negligible at high cutting speeds and for μ≥0:4 due to the sticking of the chip to the tool generated by the enhanced thermal softening. Fig.…”

“…4b. These trends have been discussed in [21] and are essentially related to the higher contribution of sticking at the tool chip interface when the cutting speed is increased. The expansion of the sticking zone is a consequence of thermal softening of the work-material along the rake face.…”

“…The detail of the tool nose and cutting surfaces geometry can only be reproduced with three dimensional approaches. However two dimensional (2D) models of orthogonal cutting, widely used in the scientific literature, are very useful to simulate phenomena such as adiabatic shearing at the primary shear zone (being the objective of this paper) or contact phenomena at the secondary zone (see for instance, previous works of the authors [2,21]). Moreover a very fine mesh is required in order to predict shear band width; this fact increases computational cost and makes really difficult the use of 3D models involving very large number of elements and long calculation time.…”

Out-of-plane failure mechanisms in LFRP composite cutting

“…Mainly macro and micro mechanical models and also combined micro macro approaches have been developed to simulate orthogonal cutting of LFRP composites. Although orthogonal cutting is not an industrial process, it is the objective of numerical analysis due to its simplicity, even in the case of metal cutting [3]. Some examples of the modeling strate gies and damage criteria used in scientific literature for orthogonal cutting of composites can be found in [4 9].…”