Study of Extension for Forming Limit of Sheet Metal at High Temperature

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03650551
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 金属加工(含鋳造)
• Research Institution: University of Electro-Communications
• Principal Investigator: SUZUKI Hideo University of Electro-Communications, Professor, 電気通信学部, 教授 (40017299)
• Co-Investigator(Kenkyū-buntansha): MURATA Makoto University of Electro-Communications, Associate Professor, 電気通信学部, 助教授 (10106883)
• Project Period (FY): 1991 – 1992
• Keywords: sheet forming / bulging / high temperature liquid / salt bath liquid / forming limit / FEM

Research Abstract

A prototype bulging machine which was used at high temperature salt bath liquid as pressure substance was made. The efforts for temperature of the liquid, materials and thicknesses of the sheet metal were experimentally examined for the pressure of the liquid, the forming limit, the bulging profiles and the strain distribution. The bulging mechanism could become clear by numerical simulation using finite element method. The temperature of is changed from 200ﾟC to 450ﾟC. The pressure of liquid, the height of bulging and strain distribution were measured at various temperature of the liquid. As the temperature of liquid was higher, the pressure decreases. The pressure value at 450ﾟC became 10% of the value at room temperature. When the bulge height is equal to 20mm, the bulge profiles and distribution made little difference at various temperatures. As the bulging height were higher, the deformation was caused at the vicinity of the bulging top. The bulging limit could be extended by the bulging method.