Direct analysis for high-strength steel frames with explicit-model of residual stresses

• A direct analysis method (DAM) for high-strength steel frames is proposed.
• Straight-line models of residual stress for high-strength steel are discussed.
• Initial imperfection and the large deflection effect are considered.
• Plastic fiber hinge method is adopted to simulate gradual yielding of a section.
• Verification examples show the feasibility and high accuracy of proposed method.

This paper proposes a direct analysis method (DAM) for design of high-strength steel members and frames allowing explicit modeling of residual stresses. A section analysis technique, based on quasi-Newton iterative scheme, is employed taking into account for the effects of residual stress. Two distributed patterns of residual stress for the welded box-sections and H-sections fabricated by high-strength steel are discussed. To consider second-order effects associated with initial imperfections and the highly inelastic behavior along the member length, the curved arbitrarily-located-hinge (ALH) element is introduced. A plastic fiber hinge model using the sectional strength-iteration surfaces is proposed for modeling of material yielding. Finally, several examples are given for verifying the accuracy and validity of the proposed method. The distinct feature of this paper is about the development of a versatile numerical procedure accounting for residual stress and geometric imperfections separately and independently for stability design of high-strength steel members.