Plastic behaviour of perforated sheets with slot-type holes under biaxial stress state

A yield criterion of sheets with slot-type holes under biaxial loading has been proposed in terms of apparent stresses. The yield criterion was confir med by finite-element analysis results. In order to analyse stretching of a perforated sheet for slot-type shadow mask by finite-element method, a yie ld function which can incorporate the apparent yield stress and the apparen t plastic contraction ratio has been obtained. The agreement between the me asured and calculated results of stretch forming of the perforated sheet wa s satisfactory. (C) 1999 Elsevier Science Ltd. All rights reserved.