Abstract

The stress analysis and optimization of the staged combined concave die under the real working pressure

Author(s): Lv Zhi-Peng, Zhu Hong-Wu, Zhou Si-Zhu

According to the structure equivalent strength optimization theory, each concave die layer’s size and inter layer interference of the flat end combined concave die were obtained by using the Lame formula. Then, the end angle and stage height were introduced into the computation model. According to the comparative analysis of the computation result, it can be found that the structure of combined concave die with both up and below steps is reasonable, and the stage height is 6mm, the end angle is 22° and the concave die with this structure was used to the forming simulation analysis. The finite element analysis software DEFORM-3D was used to simulate the process of volume forming of the part. The numbers of pressure of convex die were obtained at different simulation steps. The equivalent stress, radial stress and tangential stress distribution was obtained corresponding to different depressing magnitude of the convex die. From the analysis results of the volume molding simulation, It could be seen that during the whole process of extrusion the stress distribution of inner wall of the die was uneven. The node pressure and node coordinate of the inner wall at the finished time of the extraction, which was used for the stress analysis and optimization design again, and the force situation and optimized structure were obtained.