Tubular links for eccentrically braced frames. I: Finite element parametric study

This paper describes the development and results of a finite element parametric study of eccentrically braced frame links having hollow rectangular cross sections (i.e., tubular links). The parametric study involves over 200 combinations of geometries and properties and is divided into two parts. Part A considers a wide range of compactness ratios and link lengths to determine appropriate compactness ratio limits such that links with tubular cross sections can achieve desired rotation levels prior to significant strength degradation from local buckling. Part B of the study involves models developed with flange compactness ratios, web compactness ratios, and stiffener spacings near the proposed design limits from Part A, and also examines links having webs and flanges with different yield stresses (i.e., hybrid links). Results of the parametric study are also used to investigate the adequacy of a method for approximating link overstrength. A companion paper describes the experimental verification of the proposed design requirements.