Papers by Author: Wen Fei Peng

Abstract: High-speed and heavy-load are the targets to pursue over a long period of time in high-speed transportation. The key to solve this problem is making the components lightweight. Particularly, the hollow shaft is a new type of lightweight construction. This article explains systematically the current situation and the defects of forming technique for the hollow shafts. The solid shafts formed by Multi-Wedge Cross Wedge Rolling (MCWR) and the hollow shafts by Cross Wedge Rolling(CWR) are researched, and the key problems of hollow shafts formed in MCWR to solve emphatically are pointed out. At the same time, we obtain that MCWR will be the main technology in forming long shafts. The results in this paper provide a new direction for the hollow shafts to form in a high efficiency, energy saving and material saving method.

Abstract: Finite element model of Cross wedge rolling asymmetric shaft is established, contrasting with symmetrical rolling, the axial relative displacement of weak-side and strong-side’s metal in asymmetric cross wedge rolling is analyzed. The results show that: axial relative displacement asymmetrical rolling on the weak-side undergo the process of “increase-decrease-unchangeableness” and axial non-uniform deformation increases; axial relative displacements on the strong-side undergo the process of “decrease- unchangeableness” and axial non-uniform deformation decreases. The results provide a theoretical basis for the cross wedge rolling asymmetric shaft parts.

Abstract: Cross wedge rolling of asymmetric shaft parts has a series of problems such as the difficulty of forming, and the rules of mental flow are not clear until now. Rigid plastic FE models of the asymmetric rolling and symmetric rolling were adopted to analyze the difference of the stress and strain fields of cross section and vertical section in the two rolling processes, which illuminated the rules of the stress and strain fields in the asymmetric rolling process. The research of the stress and strain fields in asymmetric rolling has positive significance for recognizing the forming characteristics and predicting deformation defects in asymmetric rolling process.

Abstract: . Determining axial movement displacement is a key question for designing the die which is used to form asymmetric shaft parts by CWR. FE model is established in this paper, the rule of process parameters influence on axial movement displacement is also analyzed, and then influence factors on axial movement displacement are gotten. The rule is that forming angle, spreading angle and area reduction have effect on axial movement displacement; rolling temperature and the diameter of rolled part has no effect on it. The conclusion provides the foundation for further determining axial movement displacement accurately.

Abstract: Axial force in CWR is an important force and energy parameter for stable rolling, which plays an important role in studying the forming quality of asymmetric shaft-parts, section shrinkage of rolled parts and rolling of heavy area reduction. By simplifying boundary conditions of solving axial projected area in this paper, and considering the effects of frictional force generated by contact surfaces between the tools and shaped shaft-section, the formula of the axial force has been derived by analytical method; by comparison of axial force values simulated by ANSYS/LS-DYNA FE software and measured through experiment, the formula of the axial force is verified correctly. The analyzing results provide useful reference for solving process problems caused by axial force.