Flexural Capacity Formulae of Steel Cold-Formed I-Beam with Strengthened Hollow Tubular Flanges. (Dept. C)

Nader Khalil,Ayman Zaky,Ashraf Abou-Rayan

doi:10.21608/bfemu.2021.192279

Abstract

This research presents a new approach formula that predicts the flexural behavior of steel cold-formed I-beam with strengthened hollow tubular flanges. Rectangularity aspect ratio and strength of the strengthening material effect on the flexural behavior of steel cold-formed I-beam with strengthened hollow tubular flanges were studied and analyzed. A wide range of investigations was carried to figure out the effect of the hollow flanges rectangularity aspect ratio and its strengthening material. Eighty-eight numerical models were created and analyzed using the finite element technique. Three-dimensional nonlinear finite element models were prepared using eight nodes solid element with three degrees of freedom per node. Material nonlinearity and geometric effects have been considered in the model analysis. A good agreement between the experimental work done by the authors [1] and FE-model results was achieved and presented. The ultimate load values of the strengthened models were presented and compared with non-strengthened models. The increase of rectangularity aspect ratio and strength of the strengthening material lead to an increase in the section capacity of the studied models. Finally, new equations for the values of the section capacity of the strengthened sections were deduced, taking into account the factors described in this study.

Highlights

Cold-formed steel sections are widely used over the last decades, which arise in the automotive, aeronautical, and secondary structure elements.Received: (10 July, 2021) - Revised: (21 August, 2021) - Accepted: (24 August, 2021)Recently, cold-formed steel sections have been used as main structural elements, tubular flanges girder, and built-up coldformed columns
For series A, it was observed that use the rectangularity aspect ratio for flanges equal to 0.5, 1, 1.5, and 2 led to increase the section capacity compared to the control specimen by percentages ranged from 86.29% to 137.27%, 72.64% to 128.78%, 48.81% to 92.51%, and 32.55% to 66.21%, respectively
It was found that the section capacity increased by percentages ranged from 3.84% to 7.56%, 3.01% to 5.27%, 2.20% to 6.69%, and 1.88% to 6.01%, respectively compared with similar models results obtained from series A

Summary

INTRODUCTION

Cold-formed steel sections are widely used over the last decades, which arise in the automotive, aeronautical, and secondary structure elements. R. Siahaan et al [12] recommended the optimum rivet spacing of RHFCBs. Dong and Sause [13] created a FE model to study the effect of cross-section dimensions, moment distribution, transverse web stiffeners, geometric imperfections, and residual stresses, on the lateral-torsional buckling strength of hollow tubular flanges steel girder. Karunakaran and Santhi [14] presented an experimental and analytical study using the FE software ANSYS [15] to investigate the behavior of cold-formed steel rectangular hollow flanges Z-beam. They concluded that the load capacity of the studied beam by the welded connection (spot weld between the flange and web) is about 7 % more than the riveted connection. The rectangularity aspect ratio of the tubular flanges and compressive strength of the strengthening material are considered in the presented parametric study

FINITE ELEMENT MODELING

Material properties

Finite element mesh

Findings

CONCLUSIONS