Papers by Keyword: Three-Dimensional Surface

Abstract: 3D rolling is a novel technology for three-dimensional surface parts. In this process, by controlling the gap between the upper and lower forming rolls, the sheet metal is non-uniformly thinned in thickness direction, and the longitudinal elongation of the sheet metal is different along the transverse direction, which makes the sheet metal generate three-dimensional deformation. In this paper, the transition zones of spherical surface parts in 3D rolling process are investigated. Spherical surface parts with the same widths but different lengths are simulated in condition of the same roll gap, and their experimental results are presented. The forming precision of forming parts and the causes of transition zones in the head and tail regions are analyzed through simulated results. The simulated and experimental results show that the lengths of transition zones of spherical surfaces in the head and tail regions are fixed values in condition of the same sheet width and roll gap.

Abstract: Roll forming is a well known bending process and sheet metals can only be machined into two-dimensional surfaces in traditional roll forming. While with more and more personalized demands, three-dimensional surfaces are widely required. Thus, flexible rollers are used to achieve three-dimensional surfaces. And in order to optimize experimental parameters and to predict experimental results, finite element method (FEM) is developed. In this paper the set-up of flexible roll-forming is described and the process of roll forming is simulated. Then the influences of forming parameters, such as the thickness and the roll velocity, on forming quality of the sheet metal in roll forming process are discussed. The results show that the analysis of flexible roller parameters is practical for the continuous and efficient forming of three-dimensional surfaces.

Abstract: Magnetic compound fluid (MCF), a functional fluid responding to magnetic field, is expected for an application to many engineering fields. In this paper, the effect of magnetic fields on the polishing force and the restoring ability of the MCF are studied followed by the proposal of a new polishing technique using the MCF. Under a fluctuating magnetic field generated by a revolution of permanent magnet, the magnetic particles in the MCF show a higher particle disposition and an accumulating action compared to a static magnetic field. Thus the MCF generates the greater restoring ability but the lower polishing force compared to that under the static magnetic field. When the MCF under the fluctuating magnetic field is applied to the polishing as the flexible tool, it shows the high polishing performance. As a result, a feasibility of a new polishing technique using the MCF for a three-dimensional structure is confirmed.