Analysis of unbonded sandwich rolling defected length of the head based on experiments with aluminum and copper

In this paper, sandwich rolling with symmetrical thickness and materials is intensively studied. The inner metal is out of touch with both upper and lower rolls in the sandwich sheets, and all the forces are delivered from upper and lower sheets. This special character makes the relative slip distance and elongation distance appear. Then, the defected length is formed during the sandwich rolling. It verifies that the point where both inner and outer metals have the same velocity is also the point where the two metals are both deformed. Slab method is first applied in predicting the defected length of the sandwich sheets. Sandwich rolling experiments with aluminum and copper are conducted. The results obtained in this paper are also compared with those measured in experiments and calculated by stream function model recorded in references. So the model can be used in the real work conditions. It is helpful to find the best shearing position in the head of the sandwich sheets. The cost of materials is reduced based on the present model. When sheets are rolled in continual rolling passes, the defected length can be more important and serious. Specifically, if the sheets are wide, expensive and multilayer, the shearing position can be more significant to the industrial application.