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Abstract: Based on lots of drawing experiments, considering the
stress and strain state of the flange and the bottom of rectangular case
with variation of load, it is analysed that the blank holder force
brings very complex effect on load of drawing even on the load of
fracture in a larger non-rotational symmetry deformation of sheet metal
vs. punch radius. It is pointed out that the coefficient of slip
friction in the flange corner is quite sensitive to blank holder force
in a forming process, and directly affects the stress and strain state
of the flange and the part in danger of fracture. Especially at the
later stage of forming with higher surface pressure, lubrication effect
at flange turning worse leads to drawing load increasing and forming
limit decreasing.
Key words: Non-rotational symmetry drawing Blank holder force
Friction resistance Lubrication
CLC No: TG386.3
Received 20030625, received in revised form
20030928
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