Residual Stresses in Welded I‐section Members with Flame‐cut Flanges

Self Cite

Eurocode 3 design rules for the lateral stability of welded I‐members are based on the assumption of hot‐rolled flanges. In practice, a large amount of welded I‐section members is made of flame cut flanges. However, residual stresses of hot‐rolled and flame‐cut flanges are quite different. The latter are more favourable with respect to out‐of‐plane buckling. The beneficial effect of flame‐cuts commonly performed at the flanges tips is then neglected in design standards. A literature review of lateraltorsional buckling tests on welded I‐members with flame‐cut flanges highlights a scarcity of results on mono‐symmetric and/or non‐uniform members. In addition, tests are generally performed on stocky cross‐sections while welded members are usually slender. Lateral‐torsional buckling tests have thus been conducted on four S355 slender welded members made of flame‐cut flanges: two uniform beams and two tapered beams. Within both couples of beams, one had a doubly symmetric cross‐section, the other one being mono‐symmetric. Experimental results highlight the impact of tapering and/or increasing the compression flange thickness whatever the beam type.These experimental tests are then modelled with shell finite elements considering imperfections, residual stresses and material laws measured experimentally. The results are in good agreement with experimental tests. Additional finite element analyses are performed varying the residual stresses distribution. A significant impact of the flange fabrication process is confirmed, flame‐cuts increasing substantially the lateral‐torsional buckling resistance.

Section: Introductionmentioning

confidence: 58%

“…One specimen had two 200×15 mm flanges while another beam had two 200-mm wide flanges, with thickness of 15 and 20 mm. The experimental distributions are depicted in [6], where a residual stress model dedicated to welded I-section members with flame-cut flanges is also proposed.…”

Section: Imperfectionsmentioning

confidence: 99%

Lateral‐Torsional Buckling of welded I‐members with flame‐cut flanges: Experimental and numerical studies

Lebastard,

Couchaux,

Bureau

et al. 2023

Self Cite

“…Residual stresses are inserted based on the model of Lebastard et al [5] for welded I-section members with flame-cut flanges (see Figure 3).…”

Section: Numerical Modelmentioning

confidence: 99%

“…Accounting for the flame-cuts may result in a substantial increase in the out-of-plane buckling resistance of a steel member, as shown by Beyer [6] and Lebastard et al [7]- [8]. However, these studies were limited and additional results are needed to support these conclusions.…”

Section: Introductionmentioning

confidence: 99%

Out‐of‐plane flexural buckling design resistance of welded I‐members made of flame‐cut flanges

Lebastard,

Couchaux,

Bureau

et al. 2023

Self Cite

In practice, welded I‐members of steel buildings are usually made of flanges that are either wide hot‐rolled plates, or plates longitudinally divided using flame‐cuts. The residual stresses distributions resulting from both types of fabrication process are substantially different. However, the Eurocode 3 buckling design resistance of a welded I‐member in compression assumes hot‐rolled flanges, thus neglecting the beneficial impact of flame‐cuts. A parametric study is then performed regarding the out‐of‐plane flexural buckling of welded members made of flame‐cut flanges. 377 doubly symmetric members either with a uniform or a tapered cross‐section are studied. These numerical results are firstly employed to evaluate the safety and accuracy of the Eurocode 3 rules for such members by computing partial factors. The current rules proving overly conservative, two proposals are made for welded columns made of flame‐cut flanges. A first simple proposal suggests a more favorable buckling curve. A second proposal introduces an imperfection factor depending on the cross‐sectional height‐to‐width ratio. Partial factors computed for both proposals are satisfactory, the second proposal being more precise.

“…However, due to the measurement cost and complexity of residual stress, only a limited number of studies have conducted experimental investigations into the distribution of residual stress in welded components featuring flame-cut flanges. The recent study [4] investigated how imperfections in steel members impact their buckling behaviour, with a focus on residual stresses in welded members with flame-cut flanges. The researchers conducted an experimental program to measure residual stresses and developed a new model based on the results to describe this residual stress.…”

Section: Introductionmentioning

confidence: 99%

Developed numerical Analysis of Residual Stress caused by Welding and Cutting in Steel Structures

Li,

Xu,

Geißler

et al. 2023

The welding and flame‐cutting process in the steel construction are commonly used, especially for the bridge structure. Some experiments about welding and cutting have been done separately by some researchers. The results from the experiments were also compared with the results from the numerical simulation under 3D or 2D models. The agreements between those results are as good as they predicted. Therefore, the numerical simulation is a better way to analyze the quality of the steel construction after welding and cutting without time‐consuming and a large amount of cost. But there are only a few research about the numerical simulation and the some of them are aimed to verify the experiments. In this study, the calculation about the residual stresses after welding and thermo‐cutting are considered from 3D‐model into 2D‐Model. The heat source model is simply regarded as curves of time and welding energy with the algorithm methods. And no matter the change of the parameters of the model and the heat source, the heat transfer and the residual stresses can be calculated with the 2D models as fast as possible. By the means of the finite element software Abaqus, the I‐profiles are easy to receive the job results with the input parameters. The influence of the welding and cutting process are visual and direct.