New design recommendations for QN1803 high-strength stainless-steel plate girders with web openings in shear

Abstract

This study reports results of a comprehensive numerical analysis to develop new design recommendations for determining the shear resistance of QN1803 high-strength stainless-steel plate girders with web openings. A numerical model was developed and validated against experimental results reported by the authors. Following this, a detailed parametric study including 540 numerical results are presented; variables considered include the local geometrical imperfections, web slenderness, web aspect ratio, hole ratio and end cases. The parametric study results suggested that for specimens with a hole ratio of 0.7, the presence of web openings could result in a reduction of 65% in shear resistance. Also, the shear resistance of those beams containing fixed-end post increased by 9%, compared to those specimens containing free-end post. The test and numerical results were used to assess the existing design recommendations in Eurocode (EN 1993-1-4 + A1) (2015) and American National Standard (ANSI/AISC 370–21) (2021). A comparison was conducted, indicating that the design strengths were un-conservative by 7% and 4% on average for EN 1993-1-4 + A1 (2015) and ANSI/AISC 370–21 (2021), respectively. New design recommendations in the form of strength reduction factors were proposed by modifying the current design rules, and a reliability analysis was then conducted, demonstrating that the modified equations can closely predict the shear resistance of such members with web openings (only 3% difference).