This page has only limited features, please log in for full access.
Machining process modeling has been an active endeavor for more than a century and it has been reported to be able to predict industrially relevant process outcomes. Recent advances in the fundamental understanding of material behavior and material modeling aids in improving the sustainability of industrial machining process. In this work, the flow stress behavior of C45E steel is modeled by modifying the well-known Johnson-Cook model that incorporates the dynamic strain aging (DSA) influence. The modification is based on the Voyiadjis-Abed-Rusinek (VAR) material model approach. The modified JC model provides the possibility for the first time to include DSA influence in chip formation simulations. The transition from continuous to segmented chip for varying rake angle and feed at constant cutting velocity is predicted while using the ductile damage modeling approach with two different fracture initiation strain models (Autenrieth fracture initiation strain model and Karp fracture initiation strain model). The result shows that chip segmentation intensity and frequency is sensitive to fracture initiation strain models. The Autenrieth fracture initiation strain model can predict the transition from continuous to segmented chip qualitatively. The study shows the transition from continuous chip to segmented chip for varying feed rates and rake angles for the first time. The study highlights the need for material testing at strain, strain rate, and temperature prevalent in the machining process for the development of flow stress and fracture models.
Ashwin Moris Devotta; P. V. Sivaprasad; Tomas Beno; Mahdi Eynian. Predicting Continuous Chip to Segmented Chip Transition in Orthogonal Cutting of C45E Steel through Damage Modeling. Metals 2020, 10, 519 .
AMA StyleAshwin Moris Devotta, P. V. Sivaprasad, Tomas Beno, Mahdi Eynian. Predicting Continuous Chip to Segmented Chip Transition in Orthogonal Cutting of C45E Steel through Damage Modeling. Metals. 2020; 10 (4):519.
Chicago/Turabian StyleAshwin Moris Devotta; P. V. Sivaprasad; Tomas Beno; Mahdi Eynian. 2020. "Predicting Continuous Chip to Segmented Chip Transition in Orthogonal Cutting of C45E Steel through Damage Modeling." Metals 10, no. 4: 519.
In this study, the flow stress behavior of ferritic-pearlitic steel (C45E steel) is investigated through isothermal compression testing at different strain rates (1 s−1, 5 s−1, and 60 s−1) and temperatures ranging from 200 to 700 °C. The stress-strain curves obtained from experimental testing were post-processed to obtain true stress-true plastic strain curves. To fit the experimental data to well-known material models, Johnson-Cook (J-C) model was investigated and found to have a poor fit. Analysis of the flow stress as a function of temperature and strain rate showed that among other deformation mechanisms dynamic strain aging mechanism was active between the temperature range 200 and 400 °C for varying strain rates and J-C model is unable to capture this phenomenon. This lead to the need to modify the J-C model for the material under investigation. Therefore, the original J-C model parameters A, B and n are modified using the polynomial equation to capture its dependence on temperature and strain rate. The results show the ability of the modified J-C model to describe the flow behavior satisfactorily while dynamic strain aging was operative.
Ashwin Moris Devotta; P. V. Sivaprasad; Tomas Beno; Mahdi Eynian; Kjell Hjertig; Martin Magnevall; Mikael Lundblad. A Modified Johnson-Cook Model for Ferritic-Pearlitic Steel in Dynamic Strain Aging Regime. Metals 2019, 9, 528 .
AMA StyleAshwin Moris Devotta, P. V. Sivaprasad, Tomas Beno, Mahdi Eynian, Kjell Hjertig, Martin Magnevall, Mikael Lundblad. A Modified Johnson-Cook Model for Ferritic-Pearlitic Steel in Dynamic Strain Aging Regime. Metals. 2019; 9 (5):528.
Chicago/Turabian StyleAshwin Moris Devotta; P. V. Sivaprasad; Tomas Beno; Mahdi Eynian; Kjell Hjertig; Martin Magnevall; Mikael Lundblad. 2019. "A Modified Johnson-Cook Model for Ferritic-Pearlitic Steel in Dynamic Strain Aging Regime." Metals 9, no. 5: 528.