Beam-Column In-Plane Resistance Based on the Concept of Equivalent Geometric Imperfections

Abstract

Assessment of the flexural buckling resistance of bisymmetrical I-section beam-columns using FEM is widely discussed in the paper with regard to their imperfect model. The concept of equivalent geometric imperfections is applied in compliance with the so-called Eurocode's general method. Various imperfection profiles are considered. The global effect of imperfections on the real compression members behaviour is illustrated by the comparison of imperfect beam-columns resistance and the resistance of their perfect counterparts. Numerous FEM simulations with regard to the stability behaviour of laterally and torsionally restrained steel structural elements of hot-rolled wide flange HEB section subjected to both compression and bending about the major or minor principal axes were performed. Geometrically and materially nonlinear analyses, GMNA for perfect structural elements and GMNIA for imperfect ones, preceded by LBA for the initial curvature evaluation of imperfect member configuration prior to loading were carried out. Numerical modelling and simulations were conducted with use of ABAQUS/Standard program. FEM results are compared with those obtained using the Eurocode's interaction criteria of Method 1 and 2. Concluding remarks with regard to a necessity of equivalent imperfection profiles inclusion in modelling of the in-plane resistance of compression members are presented.

Buckling Resistance Criteria of Prismatic Beams Under Biaxial Moment Gradient

“…The obtained results confirm the conclusion made in Giżejowski et al (2016d), that a sufficient accuracy is obtained with the use of the M-3 mesh. This mesh is therefore used in all the FEM simulations presented hereafter.…”

“…The exercise is similar to that carried out for compression and mono-axial bending without lateral-torsional buckling, and the results are presented in Giżejowski et al (2016d).…”

A Consistent Ayrton-Perry Approach for the Flexural-Torsional Buckling Resistance Evaluation of Steel I-Section Members

“…In this context, the in-plane buckling reduction factor χip used in Figure 1 is approach dependent according the following notation: -for Approach 1: ). Such an analysis is denoted hereafter by GMNA+ in accordance to the definition presented in [6]. In the detailed analysis presented hereafter, the simply supported beam-column of HEB 300 section of the steel grade S 235 is taken into consideration.…”