Papers by Author: Xi Ning Li

Abstract: The form of blank holder and the manner of blank holder force (BHF) on the complicated parts forming are very important. The blank holder of rectangle box forming was divided long straight segments, short straight segments and corners. The forming process simulation of rectangular box was conducted by FEM based on explicit algorithm, including single-piece blank holder with constant BHF, single-piece blank holder with variable BHF, segmented blank holder with constant BHF, segmented blank holder with variable BHF. The results were analyzed according to the thinnest level of the parts. The displacement in the Z direction of blank holder in the simulation was considered, and the method of determining segmented variable blank holder force (VBHF) was proposed. Finally rectangular box was obtained by rectangular box drawing system of segmented variable BHF on the basis of the simulation result.

Abstract: The sheet forming simulation of rectangular box was conducted by finite element method (FEM), the forming process experiment, further, was investigated, so as to understand the effect of the form of blank holder and the manner of blank holder force (BHF) on the complicated parts forming. In my study, a kind of low carbon steel was investigated, and its mechanical properties were obtained by simple tension tests. The outermost contour of the blank shape was determined by “one step method”. Furthermore, the finite element model was constructed by ANSYS parametric design language (APDL), which has characteristic of grid meshing by Belytschko-Tsay (BT) shell element, applying anisotropic constitutive equation of Barlat yield criterion, dealing contact by penalty function method and using adaptive mesh algorithm in the simulation process. Then the forming process simulation of rectangular box with segmented variable BHF was conducted. On the basis of analyzing the work principle and technical parameters of XP3CEF-100 hydraulic press, the rectangular box drawing system of segmented VBHF was established, which was made of hydraulic press, rectangular box drawing die of segmented blank holder, hydraulic part of blank holder and control part. Finally the low carbon steel forming tests were fulfilled by the rectangular box drawing system on the basis of the simulation result.