Deformation behavior of variable-thickness region of billet in rib-web component isothermal local loading process

Abstract

Using the unequal-thickness billet, a good cavity fill can be obtained in the local loading process of the large-scale complex component with high ribs and thin webs. However, the folding/lap defect is prone to occur in variable-thickness region of billet (VTRB) in the forming process. In this paper, the finite element method is adopted to study the deformation behavior of VTRB in local loading process. The evolution and reasons for the folding under the different transition patterns (stepping pattern, rounding pattern, beveling pattern, etc.) and the different located positions (die partitioning boundary, web region, rib cavity, etc.) of VTRB are analyzed systemically. The results of the present study may provide a basis for determination of the transition pattern and transition condition of VTRB for large-scale unequal-thickness billet.