Analysis of the Curving Phenomenon of Curved Circular Shaped Product by the Upper Bound Analysis and the DEFORMTM-3D in Eccentric Extrusion

곡봉(曲奉)의 편심압출가공에 대하여 상계굽힘해석과 DEFORMTM-3D에 의한 굽힘해 석 비교

The kinematically admissible velocity field is developed for the eccentric extrusion of circular shaped products. The curving of product in extrusion is caused by the difference of the linearly distributed longitudinal velocity on the cross-section of the workpiece at the dies exit. The results of the eccentric extrusion by upper bound analysis show that the curvature of product increases with the increase in eccentricity of gravity center of the cross-section of workpiece at dies entrance from that of the corss-section at the dies exit end. By the DEFORMTM-3D analysis, the curving of circular shaped product in extrusion is changed by the eccentricity, die land length and the die length. The result of the analysis by DEFORMTM-3D software shows that the curvature of circular shaped product increases with the eccentricity. The two analysis and one experiment show the curving phenomenon in eccentric extrusion process.