Experimental and numerical investigation of the deep drawing process using a tractrix die – An industrial case study focused on stress and temperature analysis

Abstract

The deep drawing process of thick sheet metal for vessel production is carried out by applying a tractrix die with the absence of a blank holder, which has economic benefits for industrial production. The main aim of the paper is the development of a reliable numerical thermo-mechanical model of a silicon brass vessel manufactured by a deep drawing process in a tractrix die and a subsequent ironing process, which includes the previous assembly of the dies with reinforcing rings that creates the required prestresses. The testing of the mechanical properties of silicon brass CuZn24Si was carried out by a standard uniaxial tensile test, thus a flow curve was determined to describe the material behaviour. The initial temperatures of the environment, blank and tools were measured with an infrared thermal imager. A comprehensive finite element stress analysis of the deformable tools was carried out for the assembly phase of the dies, and for workpiece and tools in the deep drawing and ironing pro- cesses. The comparison of measured and numerically estimated temperatures had a good agreement, so the developed numerical model was confirmed and validated. This research study demonstrates how different process parameters can be investigated through a reliable and precise numerical model with comple- mentary experimental research for the optimization of industrial technology.