Analysis of Shear Localization in High-Speed Blanking of Press-Hardened 22MnB5 Steel

edge. High-speed blanking experiments with a 20 mm punch diameter and 8 m/s velocity of 2 mm thick 22MnB5-sheets (ultimate tensile strength of 1550 MPa) utilizing a relative clearance of 2.5 % are carried [...] post-process: A 'deformation shear band,' characterized by elongated grains in shear direction, is distinguished from a ‘transformation shear band’ with a change in microstructure appearing as a white layer [...] grains in 22MnB5 material. Light microscopic images show that the transfor mation shear band width varies over the sheet thickness. Independent of the occurrence of a transformation shear band, a localization …

together because QBNα k N + pB = ∇Bf(αk)−QBBα k B (20) and ∇f(αk+1) = ∇f(αk) +Q:,B(αk+1 B −αkB), (21) where |B| |N | and Q:,B is the sub-matrix of Q including columns in B. If at the kth iteration we already [...] −1 or αt > 0, yt = 1}. 12 That is, a feasible α is a stationary point of problem (11) if and only if m(α) ≤M(α). (16) From (16), a suitable stopping condition is m(αk)−M(αk) ≤ ε, (17) where ε is the tolerance [...] problem. min αA 1 2 αTAQAAαA + (pA +QANα k N)TαA subject to 0 ≤ αi ≤ C, ∀i ∈ A, (28) yTAαA = ∆− yTNαkN , where N = {1, . . . , l}\A is the set of shrunk variables. Note that in LIBSVM, we always rearrange …