Experimental and numerical studies on the tube contraction using a conical–cylindrical die

Abstract

This article describes the plastic contraction phenomenon and energy absorption of aluminum tubes, under axial compression by conical entry dies. Experiments were carried out on aluminum tubes machined from commercially available tubes. All tubes had outer diameter of 30 mm and inner diameter was made such that the tubes were obtained in the thickness range of 1–5 mm. The dies were made with semiangles of 5°, 10°, 15°, and 20°. The straight portion of die had inner diameter of 28.5 mm; hence, the diametric interference of 1.5 mm was obtained at straight portion. These dies were made with steel with sufficient thickness to treat them as rigid. The numerical simulation was done for the experiments using LS-DYNA software. Based on numerical and experimental results, the force–displacement graph characteristics for different deformations modes were discussed in detail. Effects of tube thickness and its interference with die were studied. The effect of material property on energy absorption was studied. The effect of friction on overall energy was also studied. The various associated characteristics such as tube deformation at tip and stress pattern were also studied.