D.C. Kang

Study on the deformation mode of conventional spinning of plates

Abstract The deformation mechanism of conventional spinning is studied in this paper through experiment and analysis. Three types of roller trace have been applied: straight line, concave curve and convex curve. As a result, all experiments have indicated that the deformation mode of conventional spinning of plates is quite different from that of the drawing process, but quite similar to that of shear spinning. Furthermore, when the original blank is a plate the deformation in the first pass has a decisive effect on the wall thickness distribution of the product of spinning.

Analysis of the hydromechanical deep drawing of cylindrical cups

The hydromechanical deep drawing process of aluminum cups and mild steel cups is analyzed experimentally and numerically. The effects of the process parameters on the final product quality are discussed. A working zone with a suitable maximum chamber pressure is obtained from the experimental results. The explicit finite element method is used with Hills transversely anisotropic material model for the numerical analysis. The numerical results are compared with those obtained in the experiments, process defects of local thinning are predicted and the thickness variations are discussed

Effect of anisotropy and prebulging on hydromechanical deep drawing of mild steel cups

Abstract The hydromechanical deep drawing processes of mild steel cups have been investigated experimentally and numerically. Experiments were carried out with the fixed gap method (with spacers) and the conventional method (without spacers) under different prebulging pressures. The shape variations and the thickness distributions of the workpieces were measured and discussed. The effects of anisotropy and prebulging pressure on the final product quality are discussed. The processes were analyzed by the explicit finite element code DYNA3D with the Barlat–Lian’s three-parameter material model. The numerical results are compared with those obtained in the experiments.

Experimental research on a new technology – ellipse spinning

Abstract Spinning is one of the main forming processes to produce many kinds of hollow rotary-type workpieces. Yet, this paper attempts to produce elliptical workpieces by spinning. A new device for the spinning of elliptical workpieces is designed. Conventional spinning and shear spinning without a mandrel are successfully tried with the device. The experimental results establish that the new device and the new technology are feasible and practicable, and that the spinning deformation of elliptical workpieces has some evident characteristics that are different from those of axisymmetrical workpieces.

Finite element analysis of the hydromechanical deep-drawing process of tapered rectangular boxes

Abstract Tapered rectangular boxes of aluminum and mild steel were formed using the hydromechanical deep drawing process. The experiments are described and discussed, and the process is analyzed numerically using the explicit finite element method. The numerical results are discussed and compared with the experimental results. Blanks of octagonal shape and circular shape and of various dimensions are simulated and compared, suggestions being made on this basis. The failure modes of local thinning and body wrinkling occurring in the experiments are predicted.