Outer diameter to thickness ratio effect on tube flaring behavior

Tube forming is one of the main manufacturing techniques for processing of tubular components. This process is subdivided depending on the processing i.e., tube end forming either to expand or reduce the section. One of these tube end forming techniques is a flaring process. Most applications for flaring tube ends, utilizes a conical tool for flaring the tube either till a particular deformation to achieve a desired shape or till failure to characterize the material properties. The relationship between the flaring behavior during the process based on the outer diameter and thickness of the tube was experimentally characterized in this paper for variety of tube sizes. Further flaring limits were analyzed in these considered tube sizes. For this four outer diameter to thickness ratio were experimented and results were analyzed. Further numerical simulations were performed to match the results. A closer look on the required force-displacement curve is presented and unique regions were identified. Based on the data an empirical equation is proposed. This equation provides a concept based on material or process stiffness. It is believed that once an equation is established and variables are linked to the parameter a more better prediction can be carried out for flaring the tubes.