Die Shape Design in Channel Forming Process by Compensation of Springback Error

: Shape error due to elastic recovery of formed part in unloading known as springback, is one of the most important problems of tool design in sheet metal forming processes. Many researches have been performed for proposing an efficient method to decrease or compensate springback error in sheet forming processes. These methods are usually based on iterative finite element algorithms. In this paper an analytical approach is presented for one step modification of the tooling shape in channel forming process to compensate the springback error. With the help of this approach, the optimum die shape for producing the target shape can be obtained in a few seconds. The algorithm of springback compensation by inverse FE modelling is also presented. By balancing the contact forces in this algorithm, symmetric and asymmetric sheet forming processes can be analyzed. The results of the analytical approach coincide with those of FE approach. The accuracy of the obtained results is verified by the experimental results. Asymmetric channel forming tests are performed on steel and aluminum sheets. The test results coincide to the analytical results with high precision.