A Study on Effect of Process Parameters on the Expansion of Thin Walled Aluminium 7075 Tubes

This paper deals with the effect of process parameters on the peak load and the energy absorption of the expansion of thin walled tubes using a die. The energy absorption and peak load during the expansion process were calculated for various punch angles (α) and with different expansion ratios (rp/ro) at different temperatures (T) by finite element analysis where rp is the punch outer radius and ro is the tube inner radius. The effect of these input parameters on the response parameters peak load, energy absorption and local buckling have been critically analyzed using Taguchi method. It is observed that the peak load and energy absorption of the expansion tube is influenced by expansion ratio (rp/ro), punch angle followed by tube temperature. The energy absorption of the expanded tube increases as the rp/ro ratio increases and also larger punch angle improves the energy absorption. Whereas the minimum expansion ratio (rp/ro) decreases the peak load at higher temperature and medium punch angle. The ANOVA performed on the experimental results revealed that the expansion ratio (rp/ro) is the most important process parameter that minimizes the peak load followed by punch angle and tube temperature. Also it is found that the expansion ratio improves the energy absorption.