experimental and numerical investigation of forming limit diagram of 6061 aluminum sheet

because of high strength to weight ratio, 6061 aluminum has many applications in different industries like automotive and aerospace industries and can help to reduction of fuel consumption. forming limit diagram (fld) is a useful method for sheet metal formability identification. whereas calculation of forming limit diagram by experimental tests is expensive and time consumption, in the present research two numerical criteria is presented for forming limit diagram calculation of 6061 aluminum. numerical simulation is done by abaqus software. numerical criteria of fld prediction are imported to the abaqus software to predict the forming limit diagram of 6061 aluminum. bragard method was used for calculation of experimental forming limit diagram. this method is more accurate than other methods which read forming limit strains from the elements which are near the fracture zoon. numerical criteria are ductile fracture and fld criteria which their prediction was compared with experimental forming limit diagram. results show that ductile fracture criterion has more accuracy for forming limit diagram prediction of 6061 aluminum. moreover, numerical results of punch’s force-displacement were compared with experimental results. results show that numerical results have a good agreement with experiment.