Abstract: By implementing a TANH constitutive equation, a cutting model is established with smoothed particle hydrodynamic (SPH) method to simulate the titanium alloy’s cutting process. The new model effectively avoids the element distortion problem which always occurs in the traditional cutting model based on the finite element method (FEM). Additionally, the correction parameters of TANH equation are calibrated with control variable method. Compared to the traditional Johnson-Cook constitutive model, the new model takes the strain softening into account, describes the dynamic mechanical properties of the material more accurately under a large strain condition and dynamic recrystallization mechanism. The new model also explains the formation and mechanism of saw-tooth chips very well in the cutting process of titanium alloy. Compared with experimental results, simulation results show the new cutting model predicts the chip morphology and cutting force accurately.

Key words: TANH constitutive equation, saw-tooth chips, smoothed particle hydrodynamic (SPH), titanium alloy