Experimental and Numerical Study of the Earing Defect During Square Deep Drawing Process


Deep drawing process is a very complex process which controls a lotof parameters and the associated defects. The aims of this research are to discussthe effect of parameters of the process utilized in square deep drawing processsuch ; material properties, blank size, blank shape on the height and shape ofearing defect appear of the drawn cup. Three dimensions model from low carbonsteel (AISI 1008) with thickness 0.7mm of square cup (41.4mm by 41.4mm).The finite element software (ANSYS 11) was utilized to carry out the numericalsimulation of the deep drawing process, and the experimental work result ofearing was compared with numerical of earing shape result. In this work, threetypes of the radius of die entry of 3, 5, 7mm, three shapes of the blank (circular,octagonal, and square) with various diameters, four types of radius of the punchprofile of 3, 5, 6, and 7mm had been selected to form a cup with square sides.The results show that, The circular blank give the best results according to earingdefect and useful height of the drawn cup, when square shape of blanks wereutilized, excessive earing will show in the square cup, due to non-uniformdistribution of blank material around the perimeter of the die cavity, minimummaterial in the flat side and too much material found in the die corner, whilewhen using octagonal shape of blanks which have a same surface area to thesquare blank, the earing will reduce in the corner of the cup due to extract of thetoo much material from the blank corners. The results showed a high agreementbetween the experimental work and numerical simulation reached to 85 % interms of the shapes and lengths of the earing appearing in the square cups.