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...

The aim of this paper is to investigate the connections between minimal keys and antikeys for special Sperner-systems by hypergraphs. The BoyceCodd normal form and some related problems are also studied in this paper.