Toshiya Teramae

Influence of Roller Shape on Deformation Behavior in Roll Bending of Structural Channels

Roll bending is a useful technology for manufacturing a wide variety of products in small quantities. However, the roll bending of structural channels, which have a complicated sectional shape, causes irregular deformation. On the other hand, there are fewer reports on the bending of structural channels compared to those on the roll bending of sheet-metals. The purpose of this study is to clarify the deformation behavior in the roll bending of structural channels. The present paper reports on the results from a finite element analysis of the effects of the roller shape on the deformation behavior in the roll bending of structural channels.

Computer Aided Design of Die Surface with Three‐Dimensional Free‐Form Surface for Sheet Metal Stamping

In sheet metal stamping, springback decreases forming accuracy. To increase the forming accuracy, the shape of the die surface is generally compensated manually by trial‐and‐error. Compensating the die surface with a three‐dimensional free‐form surface is difficult because the details need to be determined: (i) how to evaluate the shape difference between the formed shape and the design shape, and (ii) which part of die surface needs to be modified and to what extent. To compensate the die surface in sheet metal stamping of a three‐dimensional free‐form surface, the authors developed a system of computer aided design, which uses finite element analysis. The unique point of the system is that the evaluation of the formed shape and the modification of the die surface are carried out at each design plane independently. As a result of numerically verifying the system, the evaluated value of the formed shape and the maximum shape difference between the design shape and the formed shape decreased as the number ...

Optimum Forming Conditions for Incremental Tube Burring witha Bar Tool Using FE Simulation

Suitable tool path conditions for incremental tube burring with a bar tool are determined to obtain a uniform wall thickness distribution at the edge of a branched tube by an explicit finite element simulation. In the determination, an aluminum alloy tube, A5083-O, of 400 mm diameter and 6.0 mm wall thickness and a bar tool of 65 mm diameter are modeled. In this study, the second stage of incremental tube burring process is focused on, which is the crucial burring stage predominating the feasibility of burring process and product quality. As to the rocking condition of a bar tool at this stage, it is found that decreasing rocking angle by 5 degrees per cycle is suitable for preventing fracture and achieving high product accuracy. In addition, the simulation results show that an initial rocking angle of 45 degrees is effective in decreasing burring torque and wall thickness reduction ratio at the edge part of branched tube. This reveals that simulation is valid as a design tool for the process optimization of this multistage incremental forming.