Steel Sections Research Articles

This research investigated and compared the structural behavior of reinforced concrete straight beams and beams made with out-of-plane parts. This study focused on the influence of the location and number of out-of-plane parts, as well as encasing the beams with a steel section, on the ultimate strength, deflection, and rotation in addition to the ductility, energy absorption, and failure mode. A total of nine beams were modelized numerically, divided into three series. The first one included one straight beam, while the remaining two series included four beams each made with out-of-plane parts with and without steel sections. The beams with out-of-plane parts connected the two, three, four, and five concrete segments. The outcomes revealed that the beams made with out-of-plane parts showed less strength than straight beams, which increased the connected segments and reduced the ultimate strength capacity. The regular beam’s linearity was dissimilar to the zigzag beams, which showed a linearity of 32% and was reduced to 22%, 20%, 19.67%, and 16% for beam out-of-plane parts made with two, three, four, and five segments, respectively. Forming a zigzag in the plane of the beams reduced the cracking load, but the decrement depended on the number of parts, which led to more reduction in the yielding load. Concerning the deflection and deformations, the concrete straight beams failed in flexure, with maximum deflection occurring at the midspan of the beam, which was different for beams without plane parts, which showed a combined shear-torsional failure for which the maximum deformation occurred at the midspan with inclination of connected parts on the interior perpendicular axis. Encasing the beams’ out-of-plane parts with steel sections enhanced the structural behavior. The ductility and energy absorption of the out-of-plane parts beams were less than the straight ones, but encasing the beams with a steel section improved the ductility and energy absorption twice.

Partially Encased Composite (PEC) columns are structural elements comprising a steel section with concrete partially encased between the flanges. These columns are widely adopted in multistorey building construction, particularly as corner columns, due to their ability to optimize floor space and provide structural efficiency. Despite their advantages, PEC columns are susceptible to issues such as inadequate bond strength between steel and concrete, local buckling of steel components, and crushing of the encased concrete under axial loads. This study focuses on evaluating the global stability of a partially encased composite column with an L-shaped cross-section (L-PEC column), aiming to enhance bond strength and load-bearing capacity. The research explores the effect of incorporating castellations and corrugations on the steel web to improve the interaction between steel and concrete. Additionally, the use of steel hoops and carbon fiber-reinforced polymer (CFRP) wrapping is investigated to mitigate local buckling and concrete crushing, thereby enhancing the overall structural performance. A detailed parametric study was also carried out to assess the influence of various factors on the column's behavior.

Behaviour of screw shear connections between oriented strand board and cold-formed steel sections under ambient and post-heating conditions: An experimental and analytical investigation

This article compares numerical and experimental results obtained for axially compressed class 4 cold formed steel sections. Simulations in ANSYS Workbench 2024 R2 were conducted as part of this study, using GMNA non-linear analysis and Multilinear Isotropic Hardening (MIH) material model. The sections under analysis were steel channels made of grade S350GD+Z steel, ranging in length from 0.4 m to 1.2 m at 0.2 m increments. The objective was to represent the actual behavior of compressed cold formed sections, including local buckling and distortion. The conclusions show the adequacy of the ANSYS workbench as an effective tool for studying class 4 cold formed members. Despite the limitations due to modelling simplifications, besides identification of deformation modes, FEM analysis also allows estimating the critical load values. The need for numerical model calibration based on the experimental results has been confirmed in this study. It is particularly important for more slender members, in which the effect of geometrical imperfections becomes particularly strong. The approach proposed in this article may be used both at the design stage and in subsequent experimental verification of designed steel structures.

The aim of the work is to study the conditions of cutting the last bar of the measured length and the remaining rolled product under conditions of unstable rolling length, which are realized as a result of fluctuations in the sizes of the blanks and the temperature regime of rolling.The roll is cut into bars of the same measured length according to the order, but fluc-tuations in the length of the roll result in the last bar being either longer or shorter.If the bar is increased, then the amount of the remainder may be too large and, in order not to lose suitable rolled product and not to transfer the remainder to waste, the last bar and the remainder are cut into two bars of normal length.The work shows that the amount of the remainder, starting from which it is necessary to cut into two bars of normal length, is determined by economic feasibility, which is more ex-pensive – a bar of measured length and a remainder or two bars of normal length.An expression is given for obtaining the residual value depending on the size of the bar of the measured length, the cost coefficients of the bars of the normal length and waste. For the conditions of rolling the channel 24 on the mill 800, the remainder value is 0.86 m.It is shown that to ensure maximum profit depending on the remainder value, the last bar of the measured length can be cut in the following ways: into a bar of the measured length and the remainder, into two bars of the normal length or into a bar of the measured length and a bar of the normal length.

In construction works, composite structures are currently very popular types of structures, where a massive reinforced concrete slab is used to transfer compressive forces, and a steel section takes over the tensile forces. Composite slabs on corrugated sheets are also often used, which allow the use of time-consuming and expensive full formwork to be avoided.The cooperation of a reinforced concrete slab with a steel frame requires the development of new types of steel frame connections with a structure that allows for obtaining sufficient moment resistance during assembly and full moment resistance when working with a reinforced concrete slab.The article presents a proposal for a steel joint using an assembly table and a gusset plate intended for composite structures and methods for calculating its moment resistance

The unique building of the National Library of the Republic of Belarus includes not only urban planning, architectural, technological modern solutions, but also structural ones. One of such modern structural solutions is the use of steel-reinforced concrete structures that combine the advantages of metal and reinforced concrete structures. The article presents the results of applying a nonlinear calculation based on the diagrammatic method of stress-strain state parameters at any stage of work under load, including the construction stage, paying attention to the effects of the dead weight of steel structures and freshly laid concrete, accounting for forced deformations of concrete shrinkage, as well as the strength, deformability of complexly loaded steel-reinforced concrete elements of the building of the National Library of the Republic of Belarus, subject to the joint operation of rigid steel sections and reinforced concrete. A criterion for calculating the internal force corresponding to the strength of a composite element is proposed in the form of the maximum force at which the conditions of force equilibrium in the cross-section under consideration are met, which does not require standardization of the ultimate compressibility of the composite element components and allows taking into account the high degree of force redistribution between them in the cross-section.

Objectives: This research investigates flexural behaviour by comparing the experimental findings of two sample specimens: encased Cold Formed Steel (CFS) concrete beams and conventional reinforced concrete beams. Understanding the failure modes seen in encased CFS is critical for developing a safe and efficient composite system. Methods: The flexural behaviour of CFS encased in typical concrete beams was assessed using Four Point Bending Test. Compressive strength, flexural strength, deflection, stiffness, failure modes, load-carrying capacity, and structural performance are determined by the conventional testing methods. Crack patterns, load-deflection response, and failure mechanisms are among the observations made during the testing process. Findings: According to the experimental findings, the encased CFS beam's yield load and ultimate load are 45.32% greater than those of the reinforced concrete beam. Likewise, the encased CFS beam's deflection at yield and ultimate load is 17.73% and 14.10% lower than that of the traditional reinforced concrete beam, respectively. Novelty: Although the idea of encased steel concrete composite is not new, the use of CFS sections in concrete to improve flexural performance is a new application. It demonstrates a creative and promising method in the Civil Engineering sector. Keywords: Cold Formed Steel, Flexural behaviour, Load-deflection, Encased beam, Stiffness

Purpose: To investigate the potential application of cold-formed thin-walled steel sections in bridge construction. To review the existing calculation methods for thin-walled structures in national and international regulatory documents. To analyse the strength and deformation characteristics of the designed structure. To consider the possibility of adjusting the generally accepted calculation methodology and regulatory requirements. To provide substantiated evidence regarding the feasibility of using cold-formed thin-walled sections in the construction of bridges. Methods: Mathematical and finite element modelling, methods of structural mechanics, and the structural engineering design method were used. Results: The design of the bridge span structure, with the main beams made of cold-formed thin-walled steel sections, has been proposed, and the stress-strain state analysis has been performed. The calculations have demonstrated that the structure is capable of supporting pedestrian traffic loads without compromising its load-bearing capacity or rigidity. The research has shown that the current calculation method for thin-walled rods and the regulatory framework itself are both flawed. Practical significance: It is necessary to revise the requirements of regulatory documents on the design and calculation of bridge structures. The generally accepted methodology for calculating structures from coldformed thin-walled steel sections also needs to be adjusted so that it can be used for the calculation of bridge structures.

Until now, CFRP was used to reinforce steel sections or to extend the service life in the event of fatigue. Now, the aim of the investigations is to find out whether CFRP can be used to convert an open, thin-walled Sigma steel profile into a closed one in certain areas. The tests were carried out on 16 samples, including reference beams (unreinforced) and three different reinforcement solutions as well as two different cross-sections. The experiments included two stages. Both stages used forked supports at each end of the beam, but stage II also blocked the possibility of cross-sectional warping. The laboratory tests used the ARAMIS system and the Artec Leo 3D scanner. The comparative analysis was carried out between vertical and horizontal displacements. In addition, global and local force-displacement diagrams were developed. The proposed reinforcement method can have a significant effect on increasing the load-bearing capacity of thin-walled steel beams with slender cross-sections, which tend to distort in the form of section opening.

To improve the flexural resistance of steel–concrete composite beams while addressing environmental concerns arising from natural sand depletion and molybdenum tailings accumulation, this study proposes an innovative structural design incorporating molybdenum tailings. Four-point bending tests were performed on three newly designed steel–concrete composite beams with varying molybdenum tailings contents (0, 50 and 100%). A systematic analysis was conducted to examine the failure process, failure modes, ultimate bearing capacity, deformation characteristics and local strains at key measurement points of these composite beams under flexural failure conditions. Experimental results demonstrate that the inclusion of molybdenum tailings does not significantly alter the failure process or modes of the composite beams. However, the flexural performance is adversely affected by the addition of molybdenum tailings. Specifically, compared to the reference beam without molybdenum tailings, the composite beam with 100% molybdenum tailings exhibits a 9.03% reduction in flexural bearing capacity and a 16.39% increase in mid-span deflection. Numerical simulation results further reveal that the ultimate bearing capacity varies considerably with changes in beam section depth and steel plate thickness.

This study examines the urgency of anti-circumvention regulations in Indonesia to address the practice of circumvention that harms the domestic industry and state revenue. Circumvention, or avoidance of anti-dumping import duties in Indonesia, often occurs through diverting export routes through third countries. For example, H&I Section steel from China has entered Indonesia via Thailand. Similarly, after anti-dumping was imposed on Chinese HRC Alloy products, imports from Japan, Taiwan, and Vietnam surged. As a result, the domestic industry experienced significant sales volume and profits declines, while the country lost potential revenue. The broader impact includes reduced anti-dumping policy effectiveness, increased risk of layoffs, and factory closures due to unfair competition resulting from circumvention. This study employs qualitative normative research methods through a literature review, examining primary legal materials (such as laws and regulations from Indonesia and the U.S.), secondary sources (literature, journals, previous research results), and tertiary sources (legal dictionaries, encyclopedias). The analysis uses a comparative approach between the Indonesian and United States legal systems and examines Islamic law's perspective on these practices. The study’s findings indicate that Indonesia lacks specific regulations to address circumvention, unlike the United States, which already has a structured system. Concrete recommendations include: first, there is a need for a clear operational definition of circumvention. Second, an integrated monitoring system should be developed based on national trade data and community involvement through complaint channels. Third, the investigation procedure should allow initiation by both the authorities and external parties, with field verification and a deadline for completion. Fourth, progressive sanctions should be enforced, such as expanding anti-dumping import duties, suspending import permits, and imposing retroactive fines. Regulations can be further strengthened by adopting best practices from countries such as the United States and integrating the principles of maqashid sharia (justice, protection of property, and public welfare) so that regulations are technically effective, fair, and socially sustainable. With these measures, Indonesia can close the regulatory gap regarding circumvention, protect the domestic industry, and optimize state revenues from the international trade sector.

Induction quenching is critical for high-strength bulb flat steel, yet the influence of the heating temperature on mechanical property uniformity across sections remains underexplored. This study systematically investigates the effect of the induction heating temperature on mechanical property uniformity, prior austenite grain size, and microstructural evolution in bulb flat steel. Experimental results reveal that increasing the induction heating temperature from 845 °C to 1045 °C induces distinct mechanical responses: the yield strength disparity between the bulb and flat sections decreases by 93% (from 94 MPa), significantly improving sectional uniformity. Microstructural analysis indicates that prior austenite grain size coarsens with higher induction heating temperatures. The quenched microstructure comprises martensite and bainite in the bulb core, while the flat section is entirely martensitic. The yield strength differential between the bulb and flat sections is governed by temperature-dependent strengthening mechanisms: dislocation strengthening dominates at 845 °C~985 °C, with the bulb region exhibiting higher strength due to increased dislocation density, while grain boundary strengthening prevails at 1045 °C, where the flat region benefits from finer grains.

Abstract In this research, the flexural behavior of four composite castellated beams was studied, focusing on the structural performance and sustainability of a composite hybrid castellated I-beam design. By optimizing material distribution, the research aims to enhance load-bearing efficiency while minimizing the environmental impact of construction materials. A composite beam is created by connecting a castellated beam to a slab of self-compacting concrete using stud connectors, with a castellation degree of 25% for all specimens. Two different steel sections, IPE160 and IPE200 W-shapes, were utilized to fabricate the four castellated specimens: two featured homogeneous I-sections, while the other two employed hybrid I-sections. The experimental program entailed the procurement of components necessary for constructing beams, followed by the examination of four samples subjected to two-point loads. The results showed that the hybrid castellated beam with IPE200 on tension zone and IPE160 on compression zone gave a decrease in ultimate load capacity compared with the ultimate load of homogenous specimens IPE200 (12.81%) and increase compared with the maximum load of IPE160 (4.87%), as well as an improvement in stiffness and ductility. The experimental study demonstrates that composite hybrid castellated I-beams with differential steel strengths offer a viable solution for sustainable construction.

Buckling behavior of cold-formed high-strength steel sections: Numerical insights and design implications

Comprehensive study of quality indicators of round steel sections with bottom on a rolling and pressing technological line with a 30-80 hot screw rolling mill and a 500 kN press

Objectives: This study aims to compare the design strength of eccentrically loaded unequal leg single angles under compression according to IS 800:1984, IS 800:2007, IS 800:2007 (Amendment 2), and AISC 360-22 Specifications for structural steel buildings. Methods: Spreadsheets were developed to evaluate the compression capacities of unequal single-angle sections using all these codes. The analysis focused on unequal leg single angle connected by either longer or shorter legs, under eccentric loading conditions. Findings: IS 800:2007 (Amendment 2) significantly enhances the compression strength of unequal leg single angles compared to IS 800:2007, with increases of up to 40% for angles fastened through the longer leg and up to 87% for those fastened through the shorter leg. Compared to the AISC 360-22 LRFD method, IS 800:2007 (Amendment 2) provides up to 184% more strength for angles fastened through the longer leg and up to 179% more for angles fastened through the shorter leg, While IS 800:2007 provides up to 112% more strength for angles connected by the longer leg and up to 68% more for those connected by the shorter leg. IS 800:1984 also shows increased strength over the AISC 360-22 ASD method, with up to 67% more strength for angles connected by the longer leg and 27% more for those attached by the shorter leg. Additionally, IS 800:2007 (Amendment 2) reveals that unequal leg single angles connected by the shorter leg provide up to 56% more compression strength than those connected by the longer leg. Novelty: This research compares the capacity predicted by the latest amendment of the Indian standard code for steel design with its previous versions and the American code, focusing on the design of unequal-legged single-angle compression members. It offers valuable insights into the capacity prediction and overall structural safety, and thereby the resulting economy in the choice of steel sections. An important insight from the study is that unequal leg single angles connected by the shorter leg exhibit greater compression strength than those connected by the longer leg. Keywords: Unequal legs, Eccentrically loaded, Single angles, Steel sections, Indian codes, American codes

This study investigates the flexural performance of desert sand concrete-filled steel tube (DS-CFST) members through experimental validation and finite element modeling (FEM). An extensive database of square and circular CFST specimens subjected to pure bending was analyzed to validate an ABAQUS-based FEM. Parametric studies evaluated the influence of steel yield strength, steel ratio, stirrup confinement, and desert sand replacement ratio (r) on ultimate bending moment, stiffness, and failure modes. The results indicated that steel yield strength and section geometry significantly affected bending capacity, while desert sand substitution (r ≤ 1) had a negligible impact on capacity, reducing it by less than 3%. The FEM accurately predicted buckling patterns, moment-curvature relationships, and failure modes. New design formulas for predicting ultimate bending moment and flexural stiffness were proposed, demonstrating superior accuracy (mean error < 1%) compared to existing design codes (AIJ, AISC, GB). This study highlights that DS-CFST members, particularly circular sections, offer robust flexural performance, with enhanced ductility and uniform stress distribution. The findings underscore the potential of using desert sand as a sustainable material in concrete-filled steel tube structures without compromising structural integrity.

Abstract Numerous section profiles have been introduced to the conventional steel industry. Such sections can be applicable to stainless steel as well and the merits of the section profiles can be amplified. Sigma section is one of the innovative section profiles which offers numerous benefits including higher torsional resistance and high cross‐sectional resistance. However, the existence of longitudinal stiffeners in sigma sections might cause web crippling failure under concentrated loads. Hence, this article intends to study the web crippling behaviour of stainless‐steel sigma sections under end‐two‐flange (ETF) load case. Comprehensive numerical investigation was conducted utilizing finite element analysis (FEA) software package, ABAQUS CAE. The numerical model was successfully validated against experimental results and a parametric plan was developed. The results were analysed with each critical parameter. Ultimately, web crippling capacity of stainless‐steel sigma sections was compared with similar carbon steel sections.

Abstract: In current times, the construction sector has seen a sudden change from traditional building techniques to more advanced and cost-effective solutions. Among these, Pre-Engineered Buildings (PEBs) using cold-formed steel sections have emerged as a highly efficient alternative to conventional construction methods involving hot-rolled steel or reinforced concrete. Cold-formed sections, known for their lightweight and high strength-to-weight ratio, offer significant advantages. In the study, a comparative analysis of the industrial warehouse structure located at Nagpur was performed by using STAAD-Pro software. Also, conventional steel structure with the same dimensions and configuration was analyzed and designed using STAAD-Pro software. Dead load, Live load, and Wind load were adopted for the structures by using Indian codes.