Local Web Buckling Research Articles

Behaviour of concrete-filled circular steel tubular K-joints in wind turbine towers

The advantages of concrete-filled steel tubular lattice towers in stress efficiency, material consumption, and industrial construction are significant for the future development of ultra-long blades, ultra-high towers, and large-capacity units. The stress state of the joints is a key component of a wind tower structure. Therefore, experiments were conducted on four concrete-filled circular steel tubular (CFCST) K-joints in a lattice wind turbine tower, along with one hollow circular steel tubular (HCST) K-joint for comparison. The test results revealed that the CFCST K-joints failed due to local and overall buckling of the compression web, whereas no plastic deformation occurred on the chord. The stiffness of the CFCST K-joints significantly improved, and the stress concentration around the intersecting line was significantly reduced. Existing structural codes, both domestic and international, underestimate the bearing capacity of CFCST K-joints because the contribution of the core concrete cannot be accounted for. Finite element analyses indicate that the bearing capacity of the CFCST K-joints is dependent on the failure mode, primarily influenced by the thickness ratio τ and the angle θ. To prevent joint failure in the CFCST lattice wind turbine towers, specifically suggest τ ≤ 1 and θ ≤ 45°. Based on the bearing capacity calculation method proposed by CIDECT for HCST K-joints, design equations were obtained to predict the punching shear bearing capacity of CFCST K-joints using the least-squares method. The established formula exhibited high accuracy through regression verification.

Flexural performance of T-shape light-weight concrete filled steel tubular girder

This paper proposes an optimization study for both structure and materials to obtain an affordable, long-span, light-weight, and fast-constructing T-shape lightweight concrete-filled steel tubular (LWCFST) girder in order to be used in bridge construction. This research was performed on a hollow steel tube of Steel-52 (yield limit 360 MPa), which was filled with LWC. A set of parameters had been investigated to illustrate its effect on T-shape LWCFST girder stiffness, toughness, resilience, and ultimate carrying load capacity in order to obtain an equivalent stiffness to that of the typically used precast concrete girder. Based on design codes (EN 1994-1-1/Euro code 4 and ANSI/AISC 360-10) that permit the use of LWC as a filler material, the parameters considered were: the thickness of the steel tube, compressive strength of the filler concrete, and the bond condition between the steel tube and filler lightweight concrete. The yielding and ultimate bending capacity were determined based on the interpreted failure criteria of T-shape LWCFST girder, considering non-linear analysis for both material and loads using ANSYSWORKBENCH software. The results showed that T-shape LWCFST girder can be employed as a significant relative economic alternative to a typical precast girder in the bridge construction field, thanks to its high stiffness/weight ratio. The lightweight concrete inside was effectively employed to delay the local web buckling of the steel tube to increase its bending capacity. In addition, it reduced the total self-weight of the bridge’s superstructure by 20% compared with a typical precast concrete girder. The dominant failure of T-shape LWCFST girders was found in the upper concrete slab due to the compression stress, even though the tensile cracks in the filler concrete occurred after reaching tensile yield stress in the steel tube. Additionally, increasing the value of friction coefficient between steel tube and lightweight concrete up to 0.8 was found to significantly affect the girder stiffness and has a slight effect after, no matter how high it is.

Stiffening of I-section MRF beams against degradation due to local buckling

Moment resisting frame (MRF) beams under cyclic loading are vulnerable to local flange and web buckling. The Seismic Provisions for Structural Steel Buildings (AISC341) prescribe width-to-thickness ratio limits, which are contingent on target rotations during predefined cyclic loadings. Some rolled I-sections available in the market cannot be employed in special MRFs since they fall short of satisfying the AISC341 flange slenderness limit. Moreover, local buckling leads to a decrease in both strength and stiffness in cyclically loaded MRF beams, ultimately increasing the risk of frame side-sway collapse. This paper introduces a stiffening method aimed at improving the behavior of I-section MRF beams. The proposed method involves placing a pair of stiffeners at the plastic hinge regions. A two-phase numerical study was conducted to assess the effectiveness of this approach. In the first phase, nine unstiffened beam cross-sections with varying flange and web slenderness were considered. The slenderness limits specified by AISC341 were evaluated based on cyclic analyses of these beams. In the second phase, a parametric study was conducted on the same cross-sections, with the flange width and the placement of the pair of stiffeners considered as variables. The results revealed a substantial improvement in behavior with the addition of a pair of stiffeners. Cross-sections that failed to meet the flange slenderness limit could be used in MRFs when stiffened. The optimal location for the stiffeners was found to be significantly influenced by the flange width. Design recommendations for the ideal stiffener placement are presented in this paper.

Experimental investigation of rigid khorjini connections using reduced beam sections with diagonal and horizontal-vertical stiffeners

Steel structures with khorjini beam–column connections, used to be a popular construction practice in Iran. This paper presents a new rigid khorjini connection with reduced beam sections (RBS) for earthquake-resistant steel structures. In rigid khorjini connection, two beams pass next to the column faces without interruption and are connected to the column by vertical plates. In this research, Rigid khorjini connections with Reduced beam sections were investigated. RBS method has some disadvantages such as web local buckling and lateral torsional buckling. Therefore, to prevent these weaknesses and improve the performance of khorjini connections with reduced beam sections, web stiffeners were employed. Four different specimens were constructed and tested using IPE 140 profiles for beams: one without an RBS (KHORJINI), one with reduced beam section (KRBS), and two with RBS and web stiffeners (KRBS-HVS and KRBS-DS). Through these experimental tests, it was revealed that all specimens sustained the interstory drift angle greater than 0.06 rad without any significant loss of strength, which indicates that the Rigid khorjini connection with reduced beam sections for IPE140 profiles can perform acceptably under the conditions of AISC regulations and the use of Diagonal and Horizontal-Vertical stiffeners increased the energy dissipation and plastic rotation capacity of connections.

Fire resistance of steel-concrete cellular composite beams having different end restraints

To determine the fire resistance of steel-concrete cellular composite beams having different end restraints, constant-load heating tests and numerical simulation analyses were conducted on end-hinged and rigidly-jointed circular-holed cellular composite beams to investigate the cross-sectional temperature field, displacement changes, and damage patterns of honeycomb composite beams during the entire fire process. The results showed that there was local buckling of the end web and lower flange of the beam, and lateral instability of the lower flange, in both types of beam-end constrained cellular composite beams after the fire. The definition of the fire endurance limit of the beam-end constrained cellular composite beam is the deflection at the mid-span reaching 1/20 of the beam span. Under ISO-834 standard heating conditions, the hinge and rigid connection restrained composite beams reached their fire resistance limit at 90 min and 75 min, respectively. Due to the existence of welds, the overall torsional performance of fixed confined cellular composite beams was better under fire. After a fire, the rigid connection restrained composite beams had more complex crack distributions on the concrete surface. During heating up, the opening edge temperature of the steel beam web was higher than that of inter hole web. The recovery ratio of deformation after a fire for the hinge and rigid connection restrained composite beams was 10.6% and 7.5%, respectively. The numerical simulation results were in good agreement with the experimental results, thus verifying the correctness and validity of the finite-element model.

In‐plane stability and shear deformation analysis of the H‐beam hollow arch

SummaryH‐shaped circular arc is a relatively novel type of open‐web steel arch, and currently, no reports have been published concerning its in‐plane stability. In this paper, the elastic and elastic–plastic in‐plane stability of the H‐shaped hollow circular arch is studied by theoretical deduction combined with numerical simulation. First, the overall shear rigidity of the H‐shaped circular arch is calculated, and the elastic buckling load formula of the arch is proposed and verified considering double shear deformation under full‐span radial and uniform loading. The overall elastic buckling load deduced in this paper is reasonable according to the finite element analysis. The results indicate that the influence of shear deformation on the overall elastic buckling load of the arch decreases with the increase of the span length. The arch‐bearing capacity is the largest when the rise‐span ratio is 0.25. Second, the restriction conditions necessary for avoiding local buckling of the chordal web before integral buckling of the H‐shaped steel hollow circular arch are analyzed. Finally, the elastic–plastic failure mechanism of the H‐shaped arch under full‐span radial and uniform loading is examined, and the formula for determining the ultimate bearing capacity that is achievable before failure under full‐span radial and uniform loading is proposed. ANSYS analysis shows that under the radial uniform loading, the chordal bars will yield near 1/4L and 3/4L, and ultimately, the structural failure of the lower chord occurs in the vicinity of 1/4L. The formulas presented in this paper agree well with the results obtained from the finite element analysis and can be used as a reference for engineering applications.

Reinforcing strategies of CFRP plate for coped steel beams against local buckling

Coped steel beams have been commonly adopted in steel frame structure construction, but the existence of coped regions severely limits the ultimate load carrying capacity and will even lead to unfavorable failure modes. This paper aims to study the reinforcing strategies of carbon fiber reinforced polymer (CFRP) plates for coped steel beams against local web buckling. A total of four single coped steel beams with and without reinforced CFRP plates were fabricated and experimentally tested under different reinforcing strategies. Typical failure modes, the influence of CFRP plate layers, and pasting inclination angles were investigated and discussed. It has been found that the CFRP plate was efficient in improving ultimate load carrying capacities and prohibiting local web buckling of coped beams. The reinforcing effect was more prominent with more layers of CFRP plates, and CFRP plates with inclined pasting angles could also provide higher post-peak ductility compared to horizontal pasting. A finite element model was also established and validated against the experimental results. A subsequent parametric analysis was conducted to quantitively characterize the influence of various reinforcing strategies. The simplified calculation model was proposed based on the experimental and simulation results, which is hoped to provide further insights into the design of singled coped beams in practical engineering.

Searching for a compromise solution in cross-section size optimization problems of cold-formed steel structural members

A parametric optimization problem of cross-sectional sizes for cold-formed steel lipped channel structural members subjected to axial compression has been considered by the paper. An optimization problem is formulated as to define optimum cross-sectional sizes of cold-formed structural member taking into account post-buckling behavior (web and flange local and distortional buckling) of the member as well as structural requirements when the profile perimeter (strip width), profile thickness, design lengths of the structural member as well as material properties are constant and specified in advance. Maximization of the load-carrying capacity of the cold-formed structural member has been assumed as purpose function. The formulated parametric optimization problem has been solved by exhaustive search method using the software written in Python. As optimization results the cold-formed steel lipped channels with optimum cross-sectional dimensions have been obtained depending on the profile thickness and design lengths of the structural member. In order to obtain optimum solutions for cross-sectional dimensions of the CFS lipped channel structural members which are independent from the design flexural lengths and profile thickness, searching for a compromise solution has been performed by exhaustive search method. The obtained cold-formed steel lipped channel structural members with optimum cross-sectional sizes have higher design buckling resistance under the axial compression at the same material consumption (stripe width) comparing with the cold-formed steel lipped channels proposed by the manufacturer. Web local buckling phenomenon has been occurred in all obtained CFS lipped channel cross-sections with optimum sizes.

Flexural behavior of prestressed concrete-filled steel tubular flange beams

This research presents a numerical and analytical investigation on the structural characteristics of concrete-filled steel tubular flange beams (CFSTFBs) prestressed using steel strands under bending. CFSTFBs are found to benefit from higher flexural and shear strength compared to those of I-section beams with flat flanges. The geometrical configurations of these sections provide them with higher web local buckling resistance due to a larger flange depth-to-width ratio. A large number of existing structures, constructed with steel–concrete composite beams, need to be retrofitted due to many factors such as loss of strength as a result of service loads and environmental conditions. A potentially economical and feasible approach to strengthening these beams is upgrading them using steel prestressing strands. The finite element (FE) approach was utilized to develop a three-dimensional numerical model considering both material and geometrical nonlinearity. Accordingly, the effects of concrete strength, tubular flange shape and dimension, steel yield stress, and quantity and eccentricity of strands were included in the analysis. A simplified model, on the basis of the plastic stress distribution method (PSDM), was used to estimate the ultimate moment capacity. In order to visualize the influence of steel and concrete strength and tubular flange size on the moment capacity of CFSTFBs, several artificial intelligence (AI) algorithms were employed and a partial dependence analysis was also conducted accordingly. The ultimate capacities obtained by analytical and FE models, considering the effect of confinement, were verified by comparing the predictions with the results from experimental studies. Both analytical and FE results indicated that the prestressing strands are significantly capable of enhancing the stiffness and strength of CFSTFBs under flexural loading. It was demonstrated that the tube geometric properties can significantly control the overall performance of prestressed CFSTFBs. The results also indicated a negligible effect of the concrete compressive strength.

Reserves of the bearing capacity of metal columns as part of a single-span frame with crane loads

The search for reserves of bearing capacity and improvement of the calculation of compressed-flexural metal columns is an urgent task. This makes it possible to more fully take into account the actual operation of structures and metal savings. An analysis of these and other issues is given in this paper on the basis of theoretical and experimental studies of life-size compressed-curved columns as part of a single-story and single-span industrial building with overhead cranes. The purpose of this work was to search for reserves of the bearing capacity of compressed-bent columns as part of the diameter of one-story single-span buildings with overhead cranes. As a result of the theoretical studies carried out, a method for calculating the stability of compression-bending columns as part of a cross section with crane loads has been developed. The technique takes into account the compatibility of the work of unevenly loaded columns in the frame and the shape of the deformation of the columns under the action of an active load. The estimated length calculated for frames with crane loads according to the proposed method is less than the estimated lengths according to current standards by 8-20%. To implement the tasks set in the experiment, a stand was developed and manufactured that allows testing the column as part of the frame and applying all types of vertical and horizontal loads to it. Experimental studies of full-scale compression-bending columns as part of a frame with the application of all loads that act on them (permanent, wind and crane) at different stages of the load, up to the exhaustion of the bearing capacity, made it possible to investigate the actual stress-strain state of the columns and their movement, bending of column base plates, development of current deformations in web flanges, local buckling of flanges and webs, general buckling of columns in the frame. For reconstructed industrial enterprises, a method for determining the reserves of bearing capacity for vertical load based on multiparameter loading of the diameter is proposed.

Local web buckling of CFRP reinforced single-coped beam with slender web

The steel coped beams are commonly seen in steel structures since slotting and coping are inevitable for the fitting of steel beams. The steel coped beams with slender web, however, are prone to local web buckling, which results in decreased load carrying capacity and catastrophic failure modes. This paper is intended to investigate the feasibility of reinforcing single-coped beam with carbon fiber reinforced polymer (CFRP) plate. Totally five single-coped steel beams with or without CFRP plate reinforcement were tested. The failure processes and influences of different parameters were discussed and compared. It was found that the application of CFRP plate is effective to prohibit the development of buckling line. Thus, the load carrying capacity of CFRP reinforced single-coped beam could be three times higher than its control group. A novel finite element (FE) model was proposed and verified with experimental results. Based on the FE model, the failure mechanisms of CFRP reinforced single-coped beam were investigated. The parameter analysis was also conducted to acquire the optimal size of the CFRP plate considering its reinforcement effects. Based on both experimental and simulational results, the simplified design method of CFRP reinforced single-coped beam was also proposed.

Comparative Study of Structural Behavior for Asymmetrical Castellated (Concavely - Curved Soffit) Steel Beams with Different Strengthening Techniques

The Asymmetrical Castellated concavely – curved soffit Steel Beams with RPC and Lacing Reinforcement improves compactness and local buckling (web and flange local buckling), vertical shear strength at gross section (web crippling and web yielding at the fillet), and net section ( net vertical shear strength proportioned between the top and bottom tees relative to their areas (Yielding)), horizontal shear strength in web post (Yielding), web post-buckling strength, overall beam flexure strength, tee Vierendeel bending moment and lateral-torsional buckling, as a result of steel section encasement. This study presents two concentrated loads test results for seven specimens Asymmetrical Castellated concavely – curved soffit Steel Beams section encasement by Reactive powder concrete (RPC) with laced reinforcement. The encasement of the Asymmetrical Castellated concavely – curved soffit Steel Beams consists of, flanges unstiffened element height was filled with RPC for each side, and laced reinforced which are used inclined continuous reinforcement of two layers on each side of the Asymmetrical Castellated concavely – curved soffit Steel Beams web. The inclination angle of lacing reinforcement concerning the longitudinal axis is 45. Seven specimens with seven different configurations will be prepared and tested under two concentrated loads at the mid-third of the beam span. The tested specimen's properties are: unconfined Asymmetrical Castellated Steel Beams (Reference1), second model; Asymmetrical Castellated concavely – curved soffit Steel Beams (web and flange) confined with (RPC) only, third model; Asymmetrical Castellated concavely – curved soffit Steel Beams (web and flange) confined with (RPC) and laced reinforcement, fourth model; is same as the third model but it has one web opening with increase the depth of web post by 10 %, 20%, and 30 % as a gap between top and bottom parts of Asymmetrical Castellated concavely – curved soffit Steel Beams respectively. The results that have been obtained from the experimental part and the numerical analysis results by ABAQUS demonstrated that the increase of the gap leads to an increase in the load against the deflection curve. Sample CB8 with 122 mm gap has gained the highest load against deflection when compared with either reference sample without gap and other samples with 65 mm and 105 mm gap for concavely–curved soffit Steel Beams.

Study the Behavior of Castellated Steel Column Encasing by Different Reactive Powder Concrete Thickness with Laced Reinforcement

Castellated columns are structural members that are created by breaking a rolled column along the center-line by flame after that rejoining the equivalent halves by welding such that for better structural strength against axial loading, the total column depth is increased by around 50 percent. The implementation of these institutional members will also contribute to significant economies of material value. The main objectives of this study are to study the enhancement of the load-carrying capacity of castellated columns with encasement of the columns by Reactive Powder Concrete (RPC) and lacing reinforcement, and serviceability of the confined castellated columns. The Castellated columns with RPC and Lacing Reinforcement improve compactness and local buckling (web and flange local buckling), as a result of steel section encasement. This study presents axial load test results for four specimens Castellated columns section encasement by Reactive powder concrete (RPC) with laced reinforcement. The encasement consists of, flanges unstiffened element height was filled with RPC for each side and laced reinforced which are used inclined continuous reinforcement of two layers on each side o0f the web of the castellated column. The inclination angle of lacing reinforcement concerning the longitudinal axis is 45o. Four specimens with four different configurations will be prepared and tested under axial load at columns. The first group was the control group (CSC1) Unconfined castellated steel column, the second group was consists of Castellated columns (web and flange) confined with 17mm of (RPC), welded web, and 6mm laced reinforcement (CSC3). While group three (CSC4) consists of a Castellated steel column same as the sample (CSC3), but without using welding between two parts of the castellated steel column. Groups four and five consist of a Castellated steel column same as sample (CSC4) encased partially with reactive powder concrete (25.5 mm) (CSC5) and full encased flange with reactive powder concrete (34mm) mm (CSC6), respectively. The tested specimens' results show that an increase in the strength of the column competitive with increasing the encased reactive powder concrete thickness. And the best sample was sample CSC6 with (34mm) mm in experimental and ABAQUS results.

Seismic behavior of double-HSS links for eccentrically braced frames

This study experimentally and analytically investigates an innovative double-HSS link (DHL) used as the active link in eccentrically braced frames (EBFs). Hollow structural sections (HSS) are mechanically efficient and are used in resisting compression, torsion, and bending. Their high torsional rigidity generally eliminates lateral-torsional buckling (LTB). As a result, the plastic rotational capacity and strength degradation rate are mainly governed by flange local buckling (FLB) and web local buckling (WLB). The proposed configuration consists of a double-HSS connected to braces or columns through a center gusset plate secured by flare-bevel groove welds. The advantages of the proposed configurations are: (1) They effectively reduce the width-thickness ratios (b/t) of the flanges by using two HSSs with much shorter flanges, which considerably increases the compactness thereby enabling a large rotational capacity. (2) They provide simple and practical connection details between the link and braces or columns. (3) Typically, double-HSS sections have an e/(Mp/Vp) ratio much larger than that of wide-flange sections due to the fact that double-HSS sections have four webs which significantly increase the shear capacity. Consequently, a DHL can yield in flexure even with a length similar to that of a wide-flange shear yielding link. This in turn eliminates the need for web stiffeners. (4) The welding requirement for DHLs is less than that of the conventional shear links since no stiffeners are required. (5) The overstrength factor due to strain hardening produced by flexural yielding links is generally less than that produced by shear yielding links leading to more economical designs for the elastic portion of the frame, and (6) the iteration design process is minimized by balancing the link length and rotational demand because of a single flexural yielding mode. Furthermore, experimental and analytical results indicated that the novel DHLs can sustain larger plastic rotations and meet AISC 341′s acceptance criterion for shear yielding links. In addition, DHLs can be potentially used in D-braced EBFs with links attached to columns because the link-to-column connection of DHL remains essentially elastic. DHLs can also be used as a replaceable link which is attached to the beam and column through bolted end plates.

Experimental and numerical study on the ultimate strength of stiffened plates subjected to combined biaxial compression and lateral loads

The ultimate strength of stiffened plates subjected to combined biaxial compression and lateral loads has not been widely investigated yet by experiments. In this study, both experimental and numerical analyses were performed to study the ultimate strength and collapse behaviors of stiffened plates under the combined biaxial compression and lateral loads. And the experimental set-up provides reference for combined loads experiments. The initial deformation of the experimental specimens has been measured by laser scanning technique and taken account in the nonlinear finite element analysis. Collapse modes have also been analyzed and compared, and influences of the interaction of lateral and transverse loads on the ultimate strength have been investigated. Results show that lateral pressure would enhance the ultimate load-carrying capacity when the lateral pressure restrained deformation. And the collapse mode was the combination of local web buckling and lateral-torsional buckling of stiffeners when transverse loads were dominant load components.

Failure Mechanism of Hybrid Steel Beams with Trapezoidal Corrugated-Web Non-Welded Inclined Folds.

Literature of Steel Beams with a thin-walled trapezoidal Corrugated Web (SBCWs) shows that the capacity of SBCWs is affected by both the fatigue cracks initiated along the inclined folds (IFs) and the maximal additional stress located in the middle of the IFs. An experimental investigation on the behaviour of hybrid SBCWs under flexure is presented in this paper. This study focuses on the effect of the welding IF between the web and flanges (IFs welded or non-welded), the horizontal-fold length (200, 260, and 350 mm), and transversal flange stiffeners on the failure mechanism of the SBCW under three line load. Accordingly, six hybrid specimens were fabricated, instrumented, and tested (five SBCW specimens and one specimen with a flat web). The test setup was designed to generate shear and a moment in the testing zone via three-point bending. The results indicated that non-welded IFs specimens with or without flange stiffeners failed owing to web tearing after web and flange local buckling. The failure mode of the specimen with continuous welding between the web and flanges was local flange buckling. Finally, the paper presents a comparison between the experimental results and the European Code to predict the capacity of the flange towards local buckling. It was concluded that the non-welding the IFs affected the inelastic behaviour and the capacity of the SBCWs. In addition, the bending resistance equations presented by EN 1993-1-5 can safely predict the test results of the non-welded inclined fold and yield a high safe variation.

Buckling and post-buckling analyses of composite cellular beams

This paper aims to investigate the buckling and post-buckling analyses of composite cellular beams. For this, the numerical model is calibrated by experimental tests via post-buckling analysis. A parametric study is developed, considering six cross sections. For each section, the opening diameter and web post length are varied. Regarding the buckling analyses for the symmetrical sections, it was concluded that the end post is an important parameter in the strength of composite cellular beams that presents high web slenderness. The smaller the opening diameter, the greater the critical global shear. The variation in the height of the cellular beam had a little influence on larger diameters and web posts widths. Considering asymmetric sections, it was verified that the web post buckling did not happen for the first buckling mode. In this scenario, local web buckling of the upper tee was observed. With the height variation, there was an increase in the global shear. This is due to the fact that with the increase in height, the buckling mode was changed to the WPB, instead of local web buckling. Finally, there was a conservatism in the SCI P355 calculation recommendations, a factor that needs to be revised.

Flexural buckling behavior of corroded hot-rolled H-section steel beams

This paper mainly investigates the flexural buckling behavior of corroded hot-rolled H-section steel beams under four-point bending. A total 43 observations comprising of five experiments and thirty-eight numerical analysis results were reported to investigate the corrosion types, degrees and locations on the initial imperfections, failure modes and the flexural buckling behavior of steel beam. Based on the analysis, a recommended formula of the flexural buckling strength of corroded steel beams is derived using the direct strength method. The results show that the tested specimens fail with the local buckling of upper flange and web near the mid-span, but the failure positions and the buckling half-wavelength are different with corrosion degrees. The results also show that the yield load, buckling load and ultimate load of tested specimens decrease with the corrosion degrees increasing. When the corrosion ratio reaches 16.88%, the yield load decreases at a ratio of 21.4%, the critical buckling load decreases by 33.2%, the ultimate load after buckling decreases at a ratio of 28.3%, and the ductility coefficient decreases by 59.4%. Finally, the comparison between predicted and actual flexural strength indicates that the proposed formula can calculate the flexural buckling capacity of corroded H-section steel beams with varying degrees of corrosion.

Design method of compression-bending arches with web openings considering local buckling of web

This paper studies the in-plane stability design method of two-hinged steel arches with web openings I-shaped cross sections when local web buckling is allowed. The paper compares two types of failure mechanisms, namely, global buckling and local buckling. Based on the analogy of calculation formula of beam bending, the author proposes a formula for calculating the bearing capacity when web buckling is taken into consideration.

Local Buckling Analysis of Cold-Formed Steel Webs with Rectangular Openings

The cold-formed steel members often require web openings to save interior space and allow for building services such as mechanical piping, electrical wiring, and air conditioning systems. Stress distribution in members with openings is different from members without holes, and therefore, their characteristics, shape, and modes of buckling are dissimilar which results in distinct behavior that could increase or decrease elastic buckling capacity and ultimate strength. In this study, analytical solutions for the local buckling of cold-formed steel webs with rectangular holes subjected to compression, bending and their combination are developed and summarized. The effects of flanges and other forces such as shear and torsion are not considered. The main variables are height of openings to height of web, aspect ratio of openings, and stress distribution gradient above or under the hole. These solutions can be used for a wide range of rectangular web openings for any sections. Analyses were conducted using energy-based methods, and the results were compared with numerical data obtained from the commercial finite element software (ABAQUS). The numerical results demonstrate that the three of the six proposed formulas can be used to predict the critical buckling stress of cold-formed steel webs with rectangular holes with regard to the aspect ratio of the web opening.