Determination of Johnson-Cook equation constants for simulation of machining process using the optimization algorithm

Johnson-Cook (JC) material model takes into account the effect of strain and strain rate hardening and thermal softening, and it is used as the most applicable material model by researchers for determination of material plastic behavior during simulation of machining process. Experimental determining the constants of this equation is costly and time-consuming task. In this regard, at the present study a new method was presented and it is utilized without necessity to long time procedure and costly equipment. In this method, JC equation constants for simulation of Inconel 718 alloy machining were obtained using optimization algorithm and couple of experimental flow stress results. Obtained results using this method were compared with results of other material models determined by researchers using the experimental and analytical tests. Based on this, using the implementation of user-subroutine in finite element software, simulation of machining process at different cutting conditions was performed for each material model and results of cutting forces (two components), chip geometry (three components), and maximum temperature were compared with corresponding experiments. Finally, average of total error was reported 13.7% that is suitable compared with other material models and it provides reasonable hope that, the presented strategy is employed successfully at other investigations.