Steel Columns Research Articles

The main objective of this study is to evaluate the behavior of a typical steel beam-to-column connection with an extended end plate, isolated from a previously tested composite beam-to-steel column experimental configuration. This paper presents both analytical and numerical investigations focused on assessing the strength and stiffness of such connections. The analytical approach is based on the Component Method, while the numerical simulations were performed using Consteel and IDEA StatiCa, two finite element software tools developed for the analysis of steel structures. In Consteel, stiffness and capacity are evaluated using the Component Method, whereas IDEA StatiCa employs the Component-Based Finite Element Method (CBFEM). The results highlight the column web in shear and the end plate in tension as the most critical components. A parametric study was carried out to evaluate the influence of end plate thickness and the use of additional stiffeners on the connection’s stiffness and load bearing capacity. Both analytical and numerical results confirm the semi-rigid behavior of the connection and its ability to transfer negative bending moments. This study is part of a broader research project on the performance of semi-rigid steel and composite connections, where the interaction between the steel beam and reinforced concrete slab is considered partial. The next phase includes the calibration of nonlinear models in Abaqus and an experimental program focusing on steel and composite beam-to-column connections. The research is driven by the limited guidance offered by current design codes regarding the behavior of semi-rigid connections between steel columns and composite beams with partial interaction.

Compared to hot - rolled steel sections, cold - formed steel sections are more susceptible to instabilities. Under compressive loading, several global, distortional, and local buckling instability modes are expected to manifest. This paper summarizes results of an experimental program carried out at the National Center of Applied Research on Earthquake Engineering Laboratory (CGS) in ALGERIA to investigate the behavior up to failure of composite wood cold formed steel stud under cyclic axial loading, in which a wood core is incorporated inside the cold formed steel C stud subjected to axial cyclic loading which was compared with simple cold formed steel C stud. Six full scale columns with both ends fixed were tested, three cold formed steel C stud (600s200 - 68) and three with the same C sections reinforced with wood. Two monotonic axial concentric loading tests (one compression and one tension) and one cyclic axial loading test with different loading rate were performed on both cold - formed steel (CFS) columns and Wood CFS columns. The cyclic loading protocol was adapted from FEMA 461 with initial displacement obtained from the monotonic tests. The results showed that the local deformations (local buckling) were less noticeable for the wood CFS columns. It was also observed that, the degradation of resistance, rigidity and the total hysteretic energy dissipated were more important for composite columns.

Performance behaviour of concrete-filled corrugated steel columns predicted using machine learning on FEM and experimental data

Sectional resistance of built-up concrete-filled cold-formed steel (CF-CFS) columns under compression: Design proposal for EN 1994-1-1

Investigation into single-parameter and multi-parameter optimization methods for prestressed stayed steel columns based on nonlinear buckling analysis

Assembled H-shaped steel strut (AHSS) was applied in a deep excavation project. During the excavation process, abnormal flexural deformation of one AHSS was found. To evaluate the safety redundancies of the AHSS when its axial force reaches the designed level, a field axial loading test was conducted. It was found that, due to the weak region around the loading component, the horizontal and vertical displacements were larger for the monitoring points closer to the loading component. Steel columns showed a negligible contribution to the restriction of the horizontal displacement but relatively good vertical support of the AHSS. As compared with the normal deformation condition, the safety redundancies of the AHSS were all smaller when considering the abnormal deformation. However, the AHSS was still in a safe condition when its axial force slightly exceeded the designed value. To assess the contribution of different components of AHSS to flexural deformation and reveal the mechanism of abnormal flexural deformation, a simplified numerical simulation was conducted. The difference in horizontal movement of the wale at the two sides of each end of AHSS was found to be the leading factor causing the abnormal flexural deformation. Suggestions for avoiding such abnormal flexural deformation were given.

Deep excavations in soft soils present complex geotechnical challenges, particularly in maintaining stability during the construction process. The low shear strength and high compressibility of these soils often lead to failure mechanisms that require careful analysis. This study introduces a novel Stiffened Deep Soil Mixing retaining wall system with connectors (SDSMC) for deep excavations in soft clay. Using 3D finite element analysis, the performance of the SDSMC wall was evaluated under varying steel column profile orientations, profile sizes (HEA 100, 200, and 300), and connector configurations. Results show 66% reduction in lateral displacement and 64% reduction in ground settlement compared to conventional Deep Soil Mixing walls. Superior performance was achieved when the strong axis of the HEA (H-beam European standard, series A) section was oriented perpendicular to the lateral earth pressure (X-orientation) and with larger profiles (HEA 300). Strategic connector placement, particularly with two connectors positioned at the top and bottom of the steel column, enhanced wall performance by up to 30%. The findings validate the SDSMC system as a cost-effective, robust, and sustainable alternative for urban deep excavations in soft clay conditions, further experimental validation is recommended to confirm its performance under realistic field conditions and to account for factors such as interface behavior, construction tolerances, and long-term soil-structure interaction.

As important parameters reflecting the fire resistance of restrained steel columns, buckling and critical temperatures have been extensively studied. However, the existing simplified design methods for buckling or critical temperature are based on column models with either pin-ended or with large rotational restraints, their applications on steel columns with limited rotational restraint stiffness ratios, i.e., rotational restraint stiffness ratios smaller than the critical rotational restraint stiffness ratio, is questionable. In this paper, parametric analyses were performed on a validated numerical column model with rotational restraint stiffness ratio spanning from 0.0001 to 10.0. Additionally, the influences of slenderness ratio, load ratio, and axial restraint stiffness ratio were also considered. Results reveal significant errors when using the existing simplified design methods to predict the buckling and critical temperatures of steel columns with limited rotational restraint stiffness ratios. Based on the parametric analyses results, new prediction formulas for buckling and critical temperatures of box-section steel columns were proposed. Results of the proposed formulas are in close alignment with those of the parametric analyses across the full range of considered parameters. Moreover, the effectiveness of the proposed formulas was further validated by test results in literatures.

To investigate the compressive deformation mode and flexural mechanical performance of steel tube columns filled with aluminium foam, a series of corresponding experiments under the quasi-static eccentric compressive conditions were performed to obtain the failure deformation diagram, load-deflection curve and load-strain relationship. Based on the experimental study, A finite element model was established to analyze the mechanical performance of steel tube columns filled with aluminum foam under different loading eccentric distances. The results show that the restrained bending deformation was more pronounced in the steel tube column filled with aluminum foam, and this deformation significantly improved the overall mechanical performance as the porosity of the aluminum foam decreased. Compared with the pure steel column, the ultimate loads of the aluminium foam-filled steel tube column with porosities of 90%, 80% and 70% were increased by 87.13%, 93.41%, and 104.11%, respectively. The tensile or compressive strains of the pure steel tube column and that filled with aluminium foam respectively appeared symmetric and asymmetric phenomena because the failure deformation mode of the steel tube column was influenced by filling aluminium foam. Compared with axial compression, the ultimate vertical loads of the aluminium foam-filled steel tube column with loading eccentricities of 30 mm, 50 mm, 100 mm and 150 mm decreased by 48.78%, 60.35%, 80.19% and 88.61%. The steel tube columns filled with aluminium foam under axial compressive action and eccentric load appeared different failure modes, which were respectively the progressive crushing symmetrical deformation and bending deformation. The corresponding failure phenomena of these tubes were observed to transition from local buckling occurring at the loading or fixed end to overall bending deformation along the column length with the gradual increase of eccentricity. Furthermore, the bending moment value of the steel tube column filled with aluminium foam obtained from the experiment under different loading eccentric distances increases with the decrease of load eccentricity.

The strengthening technique by external cable prestressing, until now limited to columns with circular hollow sections (CHSs), is here extended to H-shaped steel columns. To provide an innovative general treatment, an initial imperfection, obtained from the analytical equivalence between Eurocode 3 and Ayrton–Perry formulations, is introduced. By this, a geometrically and materially nonlinear imperfection analysis (GMNIA) is performed by the finite element commercial code Abaqus. A parametric analysis identifies the deviator length, cable tension, and slenderness ratio as key parameters. Results confirm that, on the one hand, cable prestressing yields a critical load that is approximately twice that for non-prestressed elements (680 kN against 340 kN for a beam 8 m long); this effect grows with the column length. On the other hand, a simulation on a two-story frame supported by 12 columns, each 4 m long, spaced by 4 and 6 m in the two directions, under vertical ‘dead’ load shows that prestressed HEA200 columns perform as non-prestressed larger HEA220 profiles; thus, their use in this case leads to saving approximately 1.18 tons of steel; both these results are of practical interest in design of steel structures.

This paper summarizes the mechanical behavior of cold-formed thin-walled steel columns (CFTWS) under compressive loads. The research methods include experimental analysis, theoretical calculations, and numerical simulations. By introducing the research progress of CFTWS columns under compression, this paper aims to help readers quickly gain insights into the issues they are interested in. By analyzing decades of literature on the compressive research of CFTWS columns, future development trends are outlined. The analysis reveals that theoretical research, standardization, and prediction of buckling behavior for CFTWS are still inadequate. Additionally, more theoretical work is required to accurately predict the performance of CFTWS under complex loading conditions and extreme environments. This paper is capable of offering valuable references for the promotion and application of CFTWS structural technology.

Welding Sequence Optimization for Asymmetric K-Groove T-Joints in Thick Q345C Steel Columns for Microstructure and Thermal and Mechanical Properties

Purpose This study aims to present the load-carrying capacity and its most influential parameters for concrete-filled steel built-up columns (CFSBC) under axial compression. A novel analytical model has been proposed and validated to estimate the ultimate inelastic buckling strength of the CFSBC. The research also explores the effects of column length, plate thickness and carbon fibre-reinforced polymer (CFRP) confinement through finite element analysis (FEA). Design/methodology/approach The model has been proposed based on the column’s inelastic buckling. The proposed model has also been verified with the experimental database of 96 CFSBC. The parametric study is carried out using the finite element (FE)-based ABAQUS software for various parameters, such as the length of CFSBC, the plate thickness and the number of confining CFRP layers. Findings It is observed that while increasing the length of the column, the load-carrying capacity is reduced to about 12% for per metre of length increment and the reduction in the width-to-thickness ratio (b/t) reduces the load-carrying capacity to the extent of 10% to 15% for each 2 mm of thickness reduction. Owing to the change of CFRP layers from 0 to 3, there is no significant change in the results, which concludes that CFRP has a less effective role in the case of CFSBC. Research limitations/implications This study primarily focuses on the axial compression behaviour of CFSBC without considering lateral or seismic loading effects. The analytical model is validated against 96 experimental results, but further verification with larger data sets is needed for broader applicability. The FEA is conducted using ABAQUS, which may have limitations in capturing many complex real-world conditions. Additionally, CFRP confinement is analysed for up to three layers only, and its effectiveness beyond this limit remains uncertain. Practical implications This study provides a robust framework for designing CFSBC with optimised load-carrying capacity. Engineers can use the validated analytical model to estimate inelastic buckling strength, reducing reliance on costly experimental testing. The findings emphasise controlling column length and plate thickness to maximise strength, ensuring safer and more efficient structural designs. As CFRP confinement has minimal impact, its usage can be minimised, leading to cost savings. These insights are crucial for high-rise buildings and bridge applications, promoting sustainable construction by improving material efficiency, reducing waste and enhancing the overall performance of composite structural elements. Social implications The study contributes to safer and more efficient infrastructure by improving the design of CFSBC, leading to durable and cost-effective construction. Enhanced structural performance reduces the risk of failures, ensuring public safety in high-rise buildings and bridges. The optimised use of materials, especially reduced reliance on CFRP, lowers construction costs, making housing and infrastructure development more affordable. Additionally, promoting sustainable construction through efficient material use aligns with environmental conservation efforts. The findings support infrastructure resilience, benefiting communities by ensuring long-term structural reliability, reducing maintenance needs and fostering economic growth through optimised engineering solutions. Originality/value This study proposes a novel analytical model for predicting the inelastic buckling strength of CFSBC, validated with experiments and simulations, offering insights into key design factors while optimising material use and structural efficiency.

This study delves into the intricate stress and deformation behavior exhibited by double cold-formed thin-walled steel columns when subjected to non-uniform temperature conditions. By employing a multifaceted approach that encompasses theoretical analysis, rigorous experimental testing, and fire simulation, the mechanical properties of these steel columns across varying temperature spectra are meticulously examined. In the experimental phase, Q355 steel plates of 1.5 and 3 mm thicknesses are subjected to high-temperature tensile tests and fire resistance evaluations. The results unveil a stark reality: as temperatures escalate, both the yield strength and ultimate strength of the steel columns diminish precipitously while their capacity for deformation amplifies markedly. For instance, at 800 °C, the yield strength of the 1.5 mm thick steel plate stands at 384 MPa, with an ultimate strength of 519 MPa. However, this strength falters as the temperature soars to 1500 °C, with the yield strength plummeting to 303 MPa and the ultimate strength to 602 MPa. The study further employs finite element analysis, utilizing a segmented heating model to emulate the temperature gradient during a fire scenario. This simulation provides a detailed examination of the deformation of steel columns at various temperatures. The comparison between the simulation outcomes and experimental data reveals a remarkable degree of accuracy under extreme temperature conditions, thereby affirming the model’s reliability. This study innovatively integrates theoretical analysis, experimental testing, and fire simulation to systematically investigate the complex stress and deformation behavior of double cold-formed thin-walled steel columns under non-uniform temperature conditions. These insights are indispensable for the design of steel structures and fire safety assessments, offering a pivotal foundation for the advancement and optimization of steel structures operating under extreme conditions.

Experimental study on response of axially loaded steel and steel-concrete composite columns to blast loading

An effective design method of high-strength steel columns with limited datasets using physics-guided conditional tabular GAN

A novel integrated algorithm for multi-objective optimization of prestressed stayed steel columns

Seismic-resilient high-strength steel column base using stiffened replaceable cover plates: experimental and numerical study

CFRP strengthened corroded steel columns: An experimental, numerical, and machine learning investigation

Axial mechanical properties of H-shaped steel columns subject to corrosion random field