A novel 3D finite element simulation method for longitudinal-torsional ultrasonic-assisted milling

For difficult-to-cut materials such as titanium alloy, a machining method of longitudinal-torsion ultrasonic-assisted milling (LTUM) was put forward to realize the anti-fatigue manufacturing, and cutting force, cutting temperature and residual stress (RS) were analyzed by 3D finite element simulation (FES). Firstly, based on thermal mechanical coupling, a 3D FES model of ultrasonic milling was established, the simulation of the cutting force, cutting temperature and RS were realized. Then, based on the 3D FES milling model, the milling process was equivalent to the oblique cutting model, it effectively improved the computation efficiency and realized longitudinal-torsional ultrasonic compound in milling process. Base on 3D equivalent model, compared with traditional milling (TM) and LTUM from the cutting force, cutting temperature and machined-induced RS. It is concluded that the LTUM effectively reduces the cutting force and cutting temperature, increases surface compressive stress and compressive stress layer depth. Furthermore, experiments were carried out to verify the equivalent model of LTUM, it shows that the simulated results are in agreement with experimental results, and predicts cutting force, cutting temperature and RS with high precision.