Three-dimensional Rigid-plastic Finite Element Simulation For The Process Of Cross Wedge Rolling Of Hollow Shaft Parts

Cross Wedge Rolling(CWR) is a new technology and technique to produce shaft parts.In recent,studying on the process of CWR through using finite element method has been made a great progress,especially studying on solid shaft parts. However,researching on the process of CWR of hollow shaft parts is mainly to take use of experiments,even using finite element method is really few and scattered without systemic analysis.On basis of above analysis,thus,the topic of this paper is decided as "Three-dimensional rigid-plastic finite element simulation for the process of cross wedge rolling of hollow shaft parts".The results obtained in the paper could be useful for hollow shaft parts deformation by using CWR technology and has important theoretical sense and using values on improving cross wedge rolling theory.In this paper,a three-dimensional rigid-plastic finite element model has been built by using software DEFORM-3D.Compared with the experiment results,the simulation results are very close to the experiments'.Therefore,the three-dimensional finite element model of a flat wedge CWR could be correct and credible.On basis of the model,it has been studied on forming theory of the process of CWR of hollow shaft parts,including the fields of stress,strain,velocity and effective strain velocity and so on.Roll force is a very important parameter to choose CWR machine.There are many factors to affect roll force.Some primary factors which affect roll force such as process parameters including forming angle,spreading angle and area reduce rate,are studied,as well as obtain the relationships between these primary factors and roll force.Compared with solid shaft parts,the process of CWR of hollow shaft parts has an obvious difference which is that wall thicknesses of the whole shafts are not the same. The different wall thickness of hollow shafts will lead to the different resisted distortion performance,as well as affect the use of hollow shafts,it is necessary to make wall thickness be the same as much as possible.So a parameter named wall thickness contrast was defined to measure uniformity of wall thickness of the whole hollow shafts in this paper,it has analyzed that effect on different process parameters (forming angle,spreading angle and area reduce rate) and original wall thickness with wall thickness contrast.The results could be useful to choose process parameters and control the quality of hollow shaft part rolled.