Research on springback characteristic in flexible multi-points 3D stretch-bending process

Abstract

The problem of springback is one of the most significant factors affecting the forming accuracy for aluminum 3D stretch-bending parts. In order to achieve high-efficiency and high-quality forming of such kind of structural components, the springback behaviors of the AA6082 aluminum profiles are investigated based on the flexible multi-points 3D stretch-bending process (3D FSB). Firstly, a finite element simulation model for the 3D FSB process was developed to analyze the forming procedure and the springback procedure. The forming experiments were carried out for the rectangle-section profile to verify the effectiveness of the simulation model. Secondly, the influence of tension on springback was studied, which include the pre-stretching and the post-stretching. Furthermore, the influences of the bending radius and bending sequence are revealed. The results show that: (1) The numerical model can be used to evaluate the effects of bending radius and process parameters on springback in the 3D FSB process effectively. (2) The pre-stretching has little effect on the horizontal springback reduction, but it plays a prominent role in reducing the springback in the vertical direction. (3) The increase of bending deformation in any direction will lead to an increase of springback in its direction and reduce the springback in the other direction. Besides, it reduces the relative error in both directions simultaneously. This research established a foundation to achieve the precise forming of the 3D stretch-bending parts with closed symmetrical cross-section.

The experimental investigation of springback and roughness parameters in the three-point forming process using terpolymer punch

“…Springback is unavoidable, but it can be minimized by modifying tool geometry control. Ragai et al, 7 and Gao et al 8 stating that, the springback can be minimized by controlling the process parameters such as shape and dimension of tool, material properties, contact friction condition with and without lubrication, sheet thickness, and flexible multi-points 3D stretch-bending. Tekıner 9 and Liu 10 experiments concentrating on the variation of the bending radius, the thickness of the sheet, and the type of sheet material.…”

Influence of movement tracks on the forming quality of profiles fabricated by flexible stretch bending of multi-point roller dies technology

“…Flexible forming technology has been widely used in industries such as construction, rail trains, ships, aircraft manufacturing, and skull repair. [15][16][17] This technology has received widespread attention due to its die surface reconfigurability and reusability in the forming process of different parts. 18 Liang J and Li Y et al 19,20 proposed a flexible three-dimensional stretch bending forming technology, which achieved a breakthrough in one-time forming of profiles from two-dimensional to three-dimensional deformation.…”

Three-point bending straightening algorithm and verification for I-type seamless welded rail

“…Thipprakmas and Sontamino 17 investigated the influences of the coined-bead die on the spring-back characteristics during V-die bending for aluminum alloy sheets (AA1100-O) by using the finite element method and related physical experiments. Gao et al 18 investigated the spring-back behaviors of the AA6082 aluminum profiles based on the flexible multi-points 3D stretch-bending process to achieve high-efficiency and high-quality forming of such kind of structural components. Song 19 combined the power exponential hardening model of the material and the simple unloading law to determine the analytical formula of the relationship between the initial deformation of the T-section rails in the pressure straightening (means straightening by controlling loading force or pressure) process, straightening load, and loading deflection.…”