We have recently developed a novel processing method for enlarging the diameter of a hollow shaft locally through the combination of cyclic torsional load with axial compressive load. First, experiments were conducted under various processing conditions to measure the deformation in the part with an enlarged diameter. Next, numerical simulation was performed using the finite element method to investigate the distributions of stress and strain in the processed part. The effects of axial-compressive load and twist angle on deformation behavior in the enlarged part were characterized through the above experiment and analysis. In addition, the cracking mechanism in the processed part was also investigated.
