Abstract
A forming limit diagram (FLD) illustrates the behavior of sheet metal under different levels of strain. The line describing the behavior of the metal is called forming limit curve (FLC). Forming limit diagram provides information on the maximum stress the metal can undergo before fracturing or necking. The diagrams are constructed by using forming limit test of sheet metal and measuring the deformation. In this study, formability of AISI 1020 sheet metal with different thickness were investigated using experimental data obtained from forming limit test. Forming limit diagram, strain hardening exponent (n) and height of cup values have been obtained for evaluating formability of the studied material. After each test, deformation of the grid was measured by using Mylar band and the true major and true minor strains were computed. Same formability results have been found from the FLD, strain hardening exponent and height of the cup for studied materials.
Kurzfassung
Ein Diagram der Verformbarkeitsgrenze (Forming Limit Diagram (FLD)) illustriert das Verhalten von Metallblechen bei verchiedenen Dehnungsniveaus. Die Linie, die das Verhalten des Metalls beschreibt, wird Grenzformkurve (Forming Limit Curve (FLC)) genannt. Das Diagram zur Verformbarkeitsgrenze bietet Informationen über die maximalen Spannungen, die ein Metall vor einem Bruch oder einer Einschnürung aushalten kann. Solche Diagramme werden erstellt, in dem der Verformbarkeitsgrenztest für Metallbleche angewendet wird und hierbei die Deformation gemessen wird. In der diesem Beitrag zugrunde liegenden Studie wurde die Verformbarkeit von AISI 1020 Metallblechen mit unterschiedlicher Dicke untersucht, wobei die experimentell ermittelten Daten aus dem Verformbarkeitsversuch verwendet wurden. Hierbei wurden das Diagramm der Verformungsgrenze, der Verfestigungsexponent und die Höhe der jeweiligen Tassen ermittelt, um die Verformbarkeit des untersuchten Werkstoffes zu evaluieren. Nach jedem Versuch wurde die Deformation des Gitters mittels eines Mylar-Bandes gemessen und die wahren Haupt- und untergeordneten Dehnungen errechnet. Es wurden gleiche Verformbarkeitsergebnisse aus den FLD, dem Verfestigungsexponenten und der Tassenhöhe für den untersuchten Werkstoff ermittelt.
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