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# Figure 4 punch positioning errors in a x and b y

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Unformatted text preview: B = (YP + s ) + (V / 2 − ∆X P ) where A = (YP + s ) + (V / 2 + ∆X P ) ∆ LU ∆ LU ( LG ) = 0 ( LR ) = 1 c ∆ G x ( LG ) = 1 c ∆Gx ( LR ) = − 1 P c ∆ B A ( LG ) = 1 2 c ∆ BA ( LR ) = 1 2 P c ∆ X p ( LG ) = − 1 c ∆Xp ( LR ) = 1 (10) If V = 12mm , Y = 6mm , s = 1mm , and ∆X = 0 , the values in (9) can be estimated as cV (α ) = 0.08, c Xp (α ) = 0, cζ (α ) = −1, cYp (α ) = −0.14, and cs (α ) = −0.14 . (9’) Note that since the sensitivity coefficients are combined with the uncertainties based on their squared values, only the absolute values of the coefficients are important. From (9) and (9’), it can be seen that for the uncertainty of the resulting angles, the 346 T. H. M. Nguyen et al. variations of the springback angles have the most pronounced effect. The influences of variations in punch displacement Y directions and sheet thickness are of the second biggest magnitudes. While an incorrect width of the V-die only causes a limited effect, it is much more influential than the incorrectness or variations in punch centre alignment. Conversely, al...
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## This note was uploaded on 08/03/2010 for the course DD 1234 taught by Professor Zczxc during the Spring '10 term at Magnolia Bible.

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