論文ID: MT-P2022004
With the focus on the forming of a tube with differential wall thickness by the ironing of the inner surface, the interaction of the effects of punch geometry (length of parallel part LP, semiangle αP and clearance CP) on the formability and forming load is investigated by experimentally consistent finite element analysis. Results of the analysis show that LP and αP significantly affect the forming load, while CP has little effect on the load. The punch with larger LP, or the punch with smaller αP or smaller CP, realizes a higher formability because the slipping of steel tube, which is a result of shape defects, does not occur even if Δμ is small. Furthermore, it is theoretically clarified, through discussions on the forces that suppress/induce the slipping of the tube, that slipping does not occur if a large surface pressure is generated on the parallel part of the punch. Since the surface pressure generated on the parallel part of the punch during tube forming varies depending on αP and the area of the parallel part of the punch varies depending on LP, LP and αP should both be taken into account in designing the punch. On the other hand, CP does not affect the other design factors and can be designed independently.
This Paper was Originally Published in Japanese in J. Japan Soc. Technol. Plasticity 62 (2021) 87–94.