Predicting material properties of flow formed work-piece based on a finite deformation method

Flow Forming Process is a manufacturing process to deform rotating axis symmetric work-piece with rotating rollers. It is difficult to predict the behaviour of work-piece during the process because the shear and compression deformation occurs simultaneously in the shape of helix along the axis. This study presents a model which can predict the deformed geometric shape and material properties using geometric shape change and material properties of work-piece. This model is based on finite deformation theory, and assumes that the structure of the material is isotropic lattice structure. To simulate the flow forming process, firstly the axial displacement is calculated using the stress-strain relation. And then the radial displacement is calculated using the volume constancy theory. The material properties of flow formed material are easily calculated with the deformed geometry. The presented model is verified by experimenting actually, and a tensile test demonstrates the predicted material properties.