Forming Limit Diagrams are useful tools for evaluation of formability in the sheet metals. In this paper the effects of yield criteria on predictions of the right and left-hand sides of forming limit diagrams (FLDs) are investigated. In prediction of FLD, Hosford 1979, “Karafillis-Boyce” (K-B) and BBC2000 anisotropy yield functions have been applied. Whereas the prediction of FLD is based on th...

two-layer metallic sheets have wide applications in aerospace, marine, automotive and domestic industries due to their superlative characteristics. in this paper, the formability of two-layer sheet is investigated through analytical, experimental and numerical approaches. an analytical model is developed based on marciniak-kuczynski method associated hill’s non-quadratic yield criterion. formin...

Abstract The purpose of this work is to predict and analyze the formability twinning – induced plasticity steels through Marciniak-Kuczynski (MK) theory with emphasis on solutions for improving prediction results. selected constitutive equations involve Yld00-2d Barlat et al. (2003) plane stress yield function, Swift strain–hardening power law dislocation density based model proposed by Kim (20...

Forming limit diagrams (FLDs) are calculated based on both the Marciniak and Kuczynski (M-K)  model and the analysis proposed by Jones and Gillis (J-G). J-G analysis consisted of plastic deformation approximation by three deformation phases. These phases consisted of homogeneous deformation up to the maximum load (Phase I), deformation localization under constant load (phase II) and local necki...

In this article, the effect of different yield functions on prediction of forming limit curve (FLC) for aluminum sheet is studied. Due to importance of FLC in sheet metal forming, concentration on effective parameters must be considered exactly in order to have better theoretical prediction comparing experimental results. Yield function is one of the factors which are improved by adding new coe...

The forming limit diagrams (FLDs) characterizing the formability of sheet metals are usually obtained by applying proportional loadings. Nevertheless, industrial processes involve strain path changes that can modify limit-strain values. In addition, for strongly anisotropic such as Zn-Cu-Ti zinc alloy, large differences in curves (FLCs) with respect to rolling direction observed. present work, ...

An enhanced unfolding Inverse Finite Element Method (IFEM) has been used together with an extended strain-based forming limit diagram (EFLD) to develop a fast and reliable approach to predict the feasibility of the deep drawing process of a part and determining where the failure or defects can occur. In the developed unfolding IFEM, the meshed part is properly fold out on the flat sheet and tre...