FINITE ELEMENT ANALYSIS AND EXPERIMENTAL INVESTIGATIONS ON HUB FORMING IN A SHEET BY THE HOLE EXPANDING TECHNIQUE

Abstract

A numerical (finite element) simulation and experiments were carried out to form parts with hubs utilizing the hole expanding (HE) using different punch shapes (conical, flat and spherical) on AISI 1010 steel sheets with varying thickness (0.8, 1.00, 1.5 and 2mm). Five pre-hole diameters (8, 10, 12, 16 and 20 mm) were used. Effects of punch shape, sheet thickness and pre-hole diameter on load/displacement curves and failure modes were investigated. FE- predicted results showed that the punch shape, sheet thickness and pre-hole diameter were the controlling factors of the formability achieved in the process. From the experimental results, it was noticed that the required load was increased by increasing the sheet thickness and decreasing the pre-hole diameter. Effect of sheet thickness on the displacement at which maximum load occurs was not clear. FE simulation results proved to agree with to the experimental results reflecting the effect of controlling parameters and the beginning of damage modes. Limit processing curves, showing safe and unsafe regions could be determined

Keywords

• hub forming by hole expanding
• fe simulation
• punch geometry
• damage modes
• forming limit curves