Welded steel I-section columns: Residual stresses, testing, simulation and design

Cross-sectional behaviour and design of normal and high strength steel welded I-sections under compression and uniaxial bending

“…Residual stresses were incorporated into the FE models using the residual stress pattern put forward by Yun et al (2023) for both NSS and HSS welded I-sections. The residual stress pattern (Yun et al, 2022a) was developed based on the statistical analysis of a large number of existing residual stress measurements collected from the literature, as shown in Figure 5, where σ r,ft and σ r,wt are the maximum tensile residual stresses in the flanges and the web, respectively, and σ r,fc and σ r,wc are the maximum compressive residual stresses in the flanges and the web, respectively. Note that compressive and tensile residual stresses are denoted as negative and positive values, respectively, as indicated in Figure 5.…”

“…As recommended in (Yun et al, 2022a), the residual stress pattern with the mean value of the maximum tensile residual stresses predicted by equation (1) can be used for validating FE models, while the residual stress pattern with the upper characteristic value of the maximum tensile residual stresses predicted by equation (2) should be used in parametric studies in order to generate safe-sided structural performance data. The residual stress model has been successfully employed in previous numerical studies of NSS and HSS welded I-section beams (Zhu et al, 2023) and columns (Yun et al, 2022a). A separate analysis step was created in order to achieve self-equilibrium of the residual stresses prior to the application of the external loading.…”

“…Note that the correction factor b is defined as the average of the ratios of the experimental or numerical resistance r e,i to the theoretical resistance r t,i to prevent b being biased towards the experimental or numerical results with higher failure loads (Afshan et al, 2015; Meng et al, 2020), which is different from the least squares method specified in Annex D of EN 1990 (2002). A detailed description of the calculation of these key statistical can be found in (Afshan et al, 2015; Yun et al, 2022, 2022a).…”

“…The ultimate resistances of welded steel I-sections under combined loading are generally influenced by both plasticity and local instability, with the latter being increasingly dominant with increasing cross-sectional slenderness (Shi et al, 2016). Yun et al (2023) studied the member buckling behaviour of welded I-section columns, made of a wide range of steel grades, and devised a modified Eurocode 3 (EC3) design approach that accounted for the varying influence of steel strength and residual stresses. To the authors' knowledge, no equivalent systematic study to explore the influence of steel grade on the cross-sectional behaviour of welded I-sections under combined loading has yet been conducted; this is therefore the focus of the present study.…”

Behaviour, finite element modelling and design of high strength steel homogeneous and hybrid welded I‐section beams

“…The measured or generated engineering stress-strain curves were transformed into true stresslogarithmic plastic strain curves prior to incorporation into ABAQUS. Residual stresses, determined from a residual stress pattern proposed in [10] for welded I-sections with varying steel grades, were introduced into the FE models as an initial stress condition.…”