Eliminating springback error in U-shaped part forming by variable blankholder force

  • Gang Liu
  • Zhongqin Lin
  • Youxia Bao
  • J. Cao


Springback is the main concern in U-shaped part forming, which would adversely affect desired part geometries. The use of variable blankholder force in the forming process is one effective method to reduce springback. However, there has not been a systematic way to determine the blankholder force trajectory. In this article, a methodology of obtaining this blankholder force trajectory in forming a U-shaped part that considers the wrinkling limit and fracture limit in the forming process was proposed. The method was validated numerically by using the Finite Element Method to simulate the benchmark of a 2-D draw bending problem in NUMISHEET’93. With the calculated blankholder force trajectory, higher forming quality was obtained and compared with constant blankholder force cases. Springback was kept at a minimum while avoiding cracking.


sheet metal forming springback U-shaped part variable blankholder force 


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Copyright information

© ASM International 2002

Authors and Affiliations

  • Gang Liu
    • 1
  • Zhongqin Lin
    • 1
  • Youxia Bao
    • 1
  • J. Cao
    • 2
  1. 1.School of Mechanical EngineeringShanghai Jiaotong UniversityShanghaiPeople’s Republic of China
  2. 2.Department of Mechanical EngineeringNorthwestern UniversityEvanston

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