Finite element analysis of sided coined-bead technique in precision V-bending process

To fabricate the precision V-bent parts, the bending angle, inner bending radius, and outer bending radius are strictly required. These requirements result in a processing difficulty especially for the difficult-to-bend material, such as high-strength steel. In the present study, the finite element method (FEM) and laboratory experiments were used to investigate the precision V-bending process. An innovation of sided coined-bead technique was proposed for preventing the spring-back and spring-go. The conventional coined-bead technique was also investigated. Based on the stress distribution analysis, the results revealed that the mechanism of the precision V-bending process, conventional coined-bead technique, and sided coined-bead technique were clearly identified. In the precision V-bending process, the conventional coined-bead technique could only prevent the spring-back. In contrast, the sided coined-bead could prevent both the spring-back and the spring-go by setting a suitable geometry and position. The FEM simulation results showed a good agreement with the experimental results with reference to the bending forces and bending angles.