Einfluß des Formänderungsweges auf die Grenzformänderungen des Feinblechs

Abstract

Ermittlung der Grenzformänderungskurven von Feinblech aus aluminiumberuhigtem und aus titanlegiertem Tiefziehstahl ohne Vorverformung und nach unterschiedlichen Vorverformungen der Feinbleche. Deutung der durch die Vorverformungen bedingten Unterschiede in der Lage dieser Kurven.

Modelling of ductile failure in aluminium sheet forming simulation

“…[31,54]), whereas other representations were found of being almost strain-path independent (see e.g. [11,54,61,73]). At a first glance this appears paradoxical as the data represented in these different forms of the FLD are related to each other, in particular stresses and strains, see e.g.…”

“…It is known that some representations of the FLD are strongly altered by the imposed strain-paths (see e.g. [31,54]), whereas other representations were found of being almost strain-path independent (see e.g. [11,54,61,73]).…”

Intrinsic diagram of sheet metal forming limits for arbitrary strain paths

“…It is found that the pre-straining tends to decrease the limit strain ε 1 for uniaxial stretching, and to do the opposite for uniaxial stretching. The effective strain approach of Müschenborn and Sonne [28] inspire us to propose the plot of the limit value, in a forming limit diagram, with effective strain as a function of strain-rate ratioε(ρ). This diagram is not sensitive to strain path changes, especially when compared to the path dependence of FLDs.…”

A sheet metal necking formability diagram for nonlinear strain paths

“…Further information regarding standards for determining forming limit diagrams can be found in the ISO standard 5 . A critique against forming limit diagrams based on linear strain paths was raised by Müschenborn and Sonne 6 , who found that the forming limit curve does not have a constant location in the forming limit diagram but is strain path dependent. They performed a number of experiments involving bi-linear strain paths and concluded that only the final strain path is determining the formability limit.…”