Finite Element Modeling of Cold Curved Steel Rolled Beams Under Service Loads

Cold bending is an efficient method recommended by steel fabricators for curving structural steel beams. It relies solely on mechanical forces to curve the beam into the required shapes without heating. While extensive research has been conducted on fabrication processes, data on the structural performance of cold bent steel girders in service is scarce which limits its use specifically in bridge structure applications. This paper investigates the effects of cold bending on the service load capacity of steel rolled shapes. An experimental and analytical program was developed for this purpose. The experimental program consists of cold curving a rolled IPE section about its weak axis and then bending it about its strong axis by applying vertical static loads that simulate service loads. Numerically, finite element analysis was conducted and validated based on experimental results. A parametric study was then conducted to identify structural parameters that can adversely affect the resistance capacity of cold bent steel rolled beams. Results show that the reduction in resistance capacity of the cold curved steel beam depends on the configuration of the applied loads and that its structural behavior can be improved by adding stiffeners, bearing plates, modifying the end boundary conditions and introducing load eccentricities. Recommendations are finally made to improve the efficiency of cold curved steel beams in service.