Increasing of the drawing depth using tailor rolled blanks - Numerical and experimental analysis

Deep drawing is a common sheet metal forming process. In most cases, sheets with constant thicknesses are formed. At the end of the previous century, new innovative blank technologies have been established for weight saving purposes. The development of the flexible rolling process is an illustrating example for this progression. By changing the roll gap during rolling, longitudinal thickness transitions are produced. The innovative semi-finished product, which is produced in this manner, is called tailor rolled blank (TRB). Its behaviour and characteristics during further processing, especially in forming, are topics of present research. The main emphasis of this paper is placed on the idea that TRB can be used to increase the maximum deep drawing depth compared to blanks having a constant thickness. This can be realised by "weakening" certain areas of the blank in a way that the load in failure at critical areas is reduced. To ensure weight saving in addition to increasing the maximum deep drawing depth, the maximum sheet thickness of the TRB is equal to the constant thickness of the other blanks. The concept is first analysed with the help of numerical simulations and then verified by experimental work. (c) 2007 Elsevier Ltd. All rights reserved.