Numerical and Experimental Investigation of Deep Drawing Process in Square Section of Single-Layer and Two-Layer Sheets

Deep drawing of two-layer sheets is a suitable way to achieve fabrications with a desired shape and properties in sheet metal forming technology. To avoid deep drawing defects such as thinning is the most important challenge in this process. The greatest difficulties in this process are differences in material properties and in the geometry of each layer. In this paper, numerical approach has been exploited to plan and control the two-layer sheet deep drawing process. For this purpose, the three-dimensional (3D) finite element has been used. Stainless steel (St14) and aluminum (Al1100) (Al.St. and St.Al. lay-up) were selected as materials for the twolayer sheet metal. The results of simulation have been validated with experiments. Based on numerical study, the effect of process parameters on the percentage of thinning, maximum plastic strain, rupture, required forming force and Blank Holder Force (BHF) has been studied. The same procedure has been also done on one-layer sheet metal and the differences between deep drawing of one-layer and two-layer sheets have been comprehensively investigated. The results showed that maximum thinning occurs in the upper layer of die radial region as well as in the lower layer of punch radial region. Also, the maximum equivalent plastic strain in the lower layer is more than that in the upper layer.

Keywords:

Deep drawing , Two-layer sheet , Finite element method , Equivalent plastic strain , Forming Force