Finite-element-analysis of the relationship between chip geometry and stress triaxiality distribution in the chip breakage location of metal cutting operations

3D FEM simulation of chip breakage in metal cutting

“…(11) for the FE simulation of chip breakage of normalized steel AISI 1045 (C45E+N). The methodology combines three models, which describe the relationships between the 3D chip geometry parameters (helical radius r, helical pitch p h , helical angle Θ), and the thermomechanical state variables in the chip breakage location that influence the ductile fracture strain [20,37,38]. Experimental chip geometries from external longitudinal turning tests are implemented into these models in order to calculate combinations of equivalent plastic strain ε eq , temperature T, stress triaxiality η, and Lode angle parameter Θ, under which ductile fracture and accordingly chip breakage was observed in the tests.…”

“…-Model of stress state distribution [38]: A numericalempirical model was created to calculate the distribution of the stress triaxiality in the chip breakage location. It was shown that the stress state at breakage mainly develops during the chip bending phase.…”

“…The analysis of the triaxiality distribution on the chip free surface revealed that material particles on the linear part of the major cutting edge are dominated by positive triaxialities (tension) while the tool corner region is dominated by negative triaxialities (compression) [38]. This finding suggests that chip breakage initiates on the linear part of the major cutting edge since ductile fracture is supported by tension stress states.…”

“…As shown, the variations of the geometry parameters can be neglected so that the average value for each parameter is adopted for the calibration of the proposed fracture model. Figure 7 gives the distributions of equivalent strain, triaxiality, Lode angle parameter, and temperature on the chip free surface, which were calculated by the models based on earlier publications [20,37,38]. The transition from tool corner region to major cutting edge is included in the figure as well.…”

Investigation of High-Speed Cryogenic Machining Based on Finite Element Approach

“…The cutting tools are an important factor in enhancing the efficiency of machining operations. Therefore, many researchers' have been done to increase the life of cutting tools to meet industry requirements (Atlati et al (2015), Buchkremer et al (2015), Ducobu et al (2015), Fu et al (2016), Gao et al (2015), Zhu et al (2016)). Since experimental studies in the field of machining operation are costly, time-consuming and are limited so that, today researchers are using finite element methods as an efficient tool for their studies.…”