Browsing by Author "Shih, CK"

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A study on seamless tube in the planetary rolling process
(2002-02-28)
Shih, CK
;
Hsu, RQ
;
Hung, CH
;
機械工程學系
;
Department of Mechanical Engineering
In this paper, the finite element method and the dual-stream functions upper bound method are selected to analyze the tube rolling process with a planetary rolling mill. Three-dimensional elastic-plastic finite element simulations with special emphasis on the determination of the roller profile and realistic contact conditions between the rollers, workpiece and mandrel are used to reveal the deformation characteristics of seamless tube during the rolling process. In addition, the kinematically admissible velocity field of the deforming tube is described in terms of two stream functions so that the velocity components of the deforming tube can be obtained through the upper bound analysis. In both analysis methods, the equation of meshing is used to determine the contact condition between the rollers and the workpiece. The results from both methods with different variables are observed and compared. (C) 2002 Elsevier Science B.V. All rights reserved.
Experimental and numerical analyses on three-roll planetary rolling process
(2003-12-10)
Shih, CK
;
Hung, CH
;
機械工程學系
;
Department of Mechanical Engineering
This study conducts experiments on a planetary three-roll experimental apparatus and uses plasticine as the working material. Certain rolling characteristics were observed and compared with the data from finite element simulation, which include diameter of workpieces after deformation, the pitch length and threaded angle of spiral marks, and the cavity at the leading end of rolled plasticine. The comparison confirms the correctness of the simulation model for PSW. (C) 2003 Elsevier B.V. All rights reserved.
The finite element analysis on planetary rolling process
(2001-06-15)
Shih, CK
;
Hung, CH
;
Hsu, RQ
;
機械工程學系
;
Department of Mechanical Engineering
This paper is focused on using the finite element method to simulate and analyze the planetary rolling process. First, a basic geometric model of the planetary rolling mill that considers roll profiles and offset angle of the rolls was constructed. Then, a three-dimensional elastic-plastic finite element simulation was used to analyze both the deformation characteristics of this process and the distributions of stress and strain in the workpieces. During simulations, an algorithm called Equation of Meshing was proposed by which the initial contact conditions between the rollers and the workpiece were successfully derived. Finally, an optimum design method was integrated into this analysis for seeking the best design variables in order to reduce the cavity conditions in the leading end of milled steel rods. (C) 2001 Elsevier Science B.V. All rights reserved.