Empirical relationship for fracture energy in machining processes: a FEM-based investigation with AISI 1045 steel

The scarcity of experimental data poses a significant challenge when using FEM in machining processes. Accurately selecting fracture energy is crucial for cutting force optimization, and this study aims to establish an empirical relationship between fracture energy, cutting force, and machining parameters. In this work, turning operations were performed on AISI 1045 steel rods for different combinations of machining parameters and corresponding cutting forces were noted. Then, a detailed FEM model for an orthogonal turning process on AISI 1045 steel with Abaqus/Explicit was developed and the study demonstrates the need to adjust fracture energy for each combination of cutting conditions to accurately match experimental outcomes. The developed numerical model is validated with experimental results and in the validated model fracture energy is varied. The variation of cutting force for different values of fracture energy was plotted for each combination. From the plots, fracture energy corresponding to the experimental cutting force was obtained. Using a multi variable regression method, a relation of fracture energy in terms of machining parameters and cutting force was found. The findings show that the optimal fracture energy value in the model decreases with increasing cutting speed and feed.