Cold bending HPS 485W steel bridge girders

Abstract

Cold bending is commonly used for fabricating horizontally curved steel girders. In this method, mechanical loads are used to obtain the required shape by inducing permanent deformations about the girders weak axis. Closed-form solutions relating loads to deformation were recently developed for cold curving conventional steel based on elastic–perfectly plastic stress–strain curve idealization and plastic hinging. This paper extends this solution to HPS 485W, a newly developed grade of high performance steel that is increasingly being used in bridge structures. Expressions for bending loads are revisited to reflect the different post-yield characteristics of HPS 485W that is modeled using a power function. A standardized procedure that incorporates these changes is subsequently developed for cold bending HPS 485W steel sections. Three numerical examples illustrate the application of the proposed procedure for cold bending doubly and singly symmetric HPS 485W girders. They indicate that HPS 485W requires higher loads, but fewer applications compared to conventional steel, implying that fabrication costs will be lower.