Abstract
Abstract
The effect of anisotropic yield criteria is very efficient in theoretical determination of limits strain of forming limit diagram(FLD) for sheet metals. In this paper the forming limit diagrams for (AA5182/polypropylene/AA5182) [AA/PP/AA] sandwich sheets have been determined theoretically using Marciniak-Kuczynski analysis with different anisotropic yield functions (Hosford 1979 and Barlat & lian 1989). It is shown that the determination of forming limit curve using (Barlat & lian1989 criterion) with the (M-K) analysis , gave the best results compared with the other anisotropic yield criteria. Also the forming limit stress diagram is theoretically determined using Marciniak-Kuczynski analysis and (Hosford & Barlat-lian) yield criterion for sandwich sheets and AA5182 skin sheet. It is shown that the limit stress in experimental and theoretical forming limit stress curve for AA5182 skin sheet is higher than the limit stress in sandwich sheets.
Keywords : Composite materials, forming limit diagram(FLD),forming limit stress diagram (FLSD), stretch forming , anisotropic yield criterion
