Residual stresses in cold bent HE 100A steel arches

Arches are structural elements applied in roofings and bridges. They may be formed by cold bending of hot-rolled wide flange sections. The original residual stress pattern due to differential cooling in the wide flange section is altered as a result of cold bending. Residual stresses resulting from differential cooling in straight I-sections have been well documented; however, this is not the case for residual stress patterns resulting from cold bending. Residual stresses can have a significant influence on the strength and stability of arches. This paper presents experimentally measured residual stresses and a finite-element-based method for obtaining residual stresses, in cold-bent arches consisting of HE 100A wide flange sections. Residual stresses in cold bent specimens were measured with the sectioning method. A finite element model has been implemented using ANSYS 11.0. The residual stresses obtained from numerical analyses and actual measurements on cold bent steel arches do not only differ from typical hot-rolled residual stress patterns but also deviate from earlier proposed cold formed stress distributions. The results obtained from the finite element method show moderate to good agreement with experimental results.