Deformation characteristics of transitional region during local loading forming of Ti-alloy rib-web component on the double-action press

Abstract

It may be a potential way to realize high-efficiency and high-quality local loading forming on the double-action press. However, the deformation characteristics and forming quality of transitional region are the weak link during forming process. In this work, the material flow, deformation inhomogeneity, forming defect of transitional region, and their dependences on the local loading parameters were quantitatively investigated by FE simulation. It is found that due to the constraint clearance, the web material would undergo twice transverse flow with opposite directions successively in two loading steps. This phenomen is basically the same as that in the local loading forming on single-action press, while the extent of transverse material flow on double-action press is greatly smaller. Finally, the transitional region presents different strain distributions in various sub-regions. Region A and region C present a symmetric strain concentration area at rib root, while region B presents a slant strain concentration area at the middle rib. The forming quality on double-action press is better than that on the single-action press. Only a cavum defect at left rib is produced because of the transverse material flow. Constraint clearance plays the most important role in the deformation characteristics and forming quality during the local loading forming on double-action press. The transverse material flow and cavum defect can be suppressed by decreasing the constraint clearance, but the deformation inhomogeneity would increase to some extent at the same time. In addition, the friction factor and radius of left rib are the second significant factors. Increasing the friction factor and radius of left rib is helpful to suppress the transverse material flow and cavum defect, respectively. As far as the forming quality of transitional region is concerned, it is a better way to conduct the local loading forming on double-action press than on single-action press. The results will provide basis for the design of processing parameters in the local loading forming of Ti-alloy rib-web component on double-action press.