Research On The Forming Force Of Inner Increm- Ental Forming Of Copper Thin-wall Tube

In the fields of aerospace, petrochemical and industry, there are a large number of different forms of tube and different types of inner surface, how to efficiently and precisely make these inner surface is an important engineering problem. The inner incremental forming process of thin-walled tube is a novel flexible forming technology for forming the target part by pressing the thin-walled tube with the forming tool to force the metal flow. The technology uses simple equipment and forming tools to achieved continuous plastic forming on thin-walled tube, with good flexibility, low cost, green energy and other advantages. This paper studies the incremental forming force on thin-walled tube so that provides guidance for the application in engineering.Analyzed forming principle and forming process movement relationship of thin-walled tube inner incremental forming, and given the mathematical expression between the spindle speed and the rotation speed of forming tool. According to the forming principle, the principle-stress method is used to cut the element body on the thin-walled tube deformation zone, established the stress equilibrium differential equation and boundary condition of the element body, thus obtained the analytical expression of forming force on deformation zone,which provides the theoretical basis for selection the forming equipment and optimization the process parameters.The finite element analysis model of the copper thin-walled tube inner incremental forming was established, the distribution law of the equivalent stress, strain and wall thickness during forming process was obtained by ABAQUS. The effects of radial feed, roundness radius of forming tool, starting distance and wall thickness on the forming force were studied,accordingly obtained the influence of different process parameters on the forming force.The incremental experiment system of thin-walled tube was established and carried out the experiment under different process conditions, the influence of different process parameters on the forming force was analyzed by orthogonal experiment, the empirical formula of the incremental forming force was established and the correctness of the theoretical analysis and simulation analysis was verified.