Analysis on Flexible and Rigid Blank-holders Technology Applying on Thin Sheet Metal in Multi-point Forming

SUN Gang  LI Mingzhe  DENG Yushan  LI Xiangji

(Roll Forging Institute, Jilin University, Changchun 130025)

Abstract: Different technologies about rigid blank-holder forming and flexible blank-holder forming are simulated, and the influence on wrinkle, crack and forming limit from the two different technologies is also analyzed. Furthermore this process is numerically simulated by explicit software LS-DYNA for U-shaped parts with two kinds of thickness. The results show that in the rigid blank-holder forming, the formed part will wrinkle when the deformation is great, and will rupture when the blank-holder force is great. But under the same condition, by using the flexible blank-holder forming technology, the formed part is good, moreover, when the width of blank-holder surface is reduced to 1/2 of the original one. Good forming result can be obtained by increasing the blank-holder force. The flexible blank-holding technology can greatly increase the utilization efficiency of sheet metal, improve the forming limit sheet metal, and avoid various defects.

Key words: Multi-point forming  Numerical simulation  Rigid blank-holder  Flexible blank-holder  Forming limit  Sheet metal

CLC No: TG386.3

国家自然科学基金(50605028), 欧盟第六框架STREP项目DATAFORM(AST5-CT-2006-030877)和吉林大学985工程汽车工程科技创新平台资助项目. Received 20070614, received in revised form 20080127

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