Autostress Design of Steel Bridges

Abstract

Current methods of steel‐bridge design, including the AASHTO Load Factor Design method, are based on elastic analyses with only limited implicit recognition of the ability of such members to adjust for. the effects of yielding. The Autostress method, which is an extension of the Load Factor method, explicitly considers these effects at Overload and Maximum Load. At Overload, autostresses and automoments caused by local plastic deformations assure elastic behavior; i.e., shakedown, after initial passages of heavy permit loads. Limit‐state criteria for riding quality and concrete cracking are considered. At Maximum Load, the strength of continuous bridge members is determined with a new plastic‐design method for noncompact members. The new design criteria can be used for the design of new bridges and for the rating of existing bridges.