Determination of stretch-bendability limits and springback for T-section beams

A mathematical model for stretch-bending of T-section beams is introduced in the present study. A complete analysis using the strength-of-materials approach is carried out for two different locations of the flange of the beam with respect to the forming die. The first position is called “flange in” which makes the flange in complete contact with the surface of the forming die and toward the center of curvature of the die. The second position is called “flange out” which makes the web of the beam toward the center of curvature of the die. The variations of the applied bending moment with the applied axial load for fully elastic, primary-plastic, and secondary-plastic regimes are derived. The effect of the web thickness on stretch-bendability as well as springback are presented and discussed.