Numerical investigation on the residual stresses of roller-bent circular-hollow-sections: Fid-Bau Portal

Numerical investigation on the residual stresses of roller-bent circular-hollow-sections

Thanasoulas, Ilias D. / Gantes, Charis J.

Abstract The membrane residual stress and strain formations of roller-bent steel members, comprising Circular-Hollow-Sections (CHS), are examined in the present study. Detailed finite element models are developed to simulate the curving procedure of CHS workpieces in a reliable manner, by means of implicit analyses accounting for geometric, contact and material nonlinearities. A mesh convergence study is carried out, followed by an extensive parametric study aiming at assessing the influence of the main roller-bending characteristics on the developed stress/strain distributions. The examined parameters include the CHS diameter and thickness, the radius of curvature, the steel yield stress, the bending length, the diameter of bending rolls and the encapsulating angle of bending dies. Variations are encountered in the locked-in stress formations, attributed to the presence of shear and transverse stresses in the CHS workpiece within the three-point-bending length. The obtained residual stress distributions are summarized, and a characteristic distribution is proposed on the basis of the locked-in formations that are encountered most commonly.

Highlights • Computational study on the roller-bending process of steel members. • Parametrical analyses of the main roller-bending characteristics. • Residual stress model for roller-bent arches of circular-hollow-sections.