Shear Buckling Strength Research Articles

Wall-frame interaction of steel plate shear wall strengthened by foam-infilled corrugated CFRP panel

In this study, a foam-infilled corrugated CFRP panel was proposed to improve the bearing capacity and energy dissipation of infill panels for steel plate shear wall (SPSW) as an effective lateral force resisting system in constructions. The horizontal corrugated CFRP panels were fixed to both sides of the inner steel plate, and polyethylene terephthalate (PET) foams were infilled between the steel plate and the corrugated panel. With the aim of fully exploiting the strength, the interaction between the infill panel and the boundary frame elements was investigated to guide the design of vertical boundary elements (VBEs) and horizontal boundary elements (HBEs). Equations for the shear buckling strength of the CFRP-steel sandwich shear wall (CFSSW) were analytically obtained to facilitate the design of the buckling restraining effect. Theoretical analyses of the force transfer mechanism between the wall panel and the boundary frame element were also presented. In addition, finite element models were developed to investigate the effect of the bending stiffness of the VBE on the load carrying capacity. Based on the theoretical and numerical analyses, the response of single-span two-story FE models for SPSW and CFSSW with steel frames (SF) were compared to further evaluate the hysteretic behavior of CFSSW. Finally, simplified models for CFSSW with tension-compression and tension-only trusses were proposed to facilitate practical design.

Effect of variable-thickness webs on shear buckling performance of welded steel plate girders: Numerical analysis and proposed design rules

The use of welded steel members with varying thickness webs is becoming more popular and is often used as plate girders to accommodate varying loading distributions. Such variable-thickness steel plates are more susceptible to experiencing out-of-plane shear buckling, particularly in the thinner sections. However, no research work has been described investigating the shear buckling strength of welded steel plate girders with variable-thickness webs. This study presents an extensive numerical analysis to examine the shear buckling strength of such steel members with variable-thickness webs. Finite element (FE) models incorporating the material non-linearity and initial geometric imperfections were developed. To validate the modelling approach employed in this investigation, a total of 41 experimental results reported by the authors and other researchers were used. A detailed parametric study was subsequently undertaken, exploring various variables including local geometrical imperfections, aspect ratio, thickness change ratio, residual stress, and yield strength. To assess the accuracy of the current design regulations, the test and parametric study results were compared against design strengths. Upon comparison, the current design regulations as specified in Chinese Code (GB 50017), American Specification (ANSI/AISC 360-10) and Eurocodes (EN 1993-1-5) are over-conservative when computing the strength of such members with variable-thickness webs. Finally, new design rules covering both cases of variable-thickness and constant-thickness webs are proposed. A reliability analysis was conducted, and the values of β were 2.87, 3.00, and 3.04, respectively, indicating that new design methods developed in this study could closely determine the shear buckling strength of such welded steel plate girders with variable-thickness webs.

Material properties and shear behaviour of QN1803 high-strength stainless steel plate girders

QN1803, a high-strength stainless steel, has been developed recently, and its tensile yield strength can be approximately 40 % (or more) higher than the commonly-used EN1.4301, while its cost is 20 % lower due to its reduced nickel content. This high-performance material can potentially be used in many applications, and one such application is plate girders. However, no experimental work has been undertaken. This issue is addressed herein. A detailed experimental study comprising seven plate girder tests is presented in this study. The plates were austenitic grade QN1803 and EN 1.4301, and the depth of web was fixed as 500 mm, 600 mm and 700 mm. For comparison, specimens with rigid end posts were also tested. The initial geometrical imperfections were first determined from three-dimensional (3D) scanning. Finite element models (FEMs) incorporating the material non-linearity and initial geometric imperfections are then developed and validated against the test results. A total of 15 tensile coupon tests are performed to investigate the effects of rolling directions on the material properties, with longitudinal coupons, diagonal coupons, and transverse coupons all being tested. The test results indicated that the 0.2 % proof stresses of the transverse coupons were approximately 8.5 % higher than that of the longitudinal coupons. The plate girder tests suggested that the shear buckling strength of QN1803 members was increased by 38.2 % on average compared to EN 1.4301 members. The design rules for determining the shear buckling strength of plate girders as provided in Eurocodes (EN 1993–1–4 +A1) (2015), North American Specification (ANSI/AISC 370–21) (2021) and those proposed by Chen et al. (2023) were evaluated. The results demonstrated that the design formulas proposed by Chen et al. (2023) can closely calculate the shear buckling strength of such QN1803 members.

Design method of HSS welded H-section beams subjected to bending-shear combination

High-strength steel (HSS) welded H-section beams are increasingly used in steel structures considering their advantage of high strength, but the stability is a concern especially near the supports, where the beams are prone to buckling under the combined actions of bending and shear. In this paper, finite element method was used to analyze the mechanical performance of HSS welded H-section beams under shear and bending-shear loads. A parametrical analysis for the H-section beams under pure shear loads was conducted, and a new shear buckling coefficient calculation method considering the interaction between plates was proposed. This coefficient was then applied to calculate the shear strength, and a design method for shear buckling strength based on the direct strength method (DSM) was proposed. Finally, a new bending-shear interaction curve was developed to predict the ultimate resistance of HSS welded H-section beams under bending-shear combination, and the reliability analysis results demonstrate the feasibility and safety of the design method proposed in this paper for HSS welded H-section beams.

A study on effective rehabilitation method of shear buckling strength by CFRP in steel girder

To increase the shear strength of steel girders, several conventional methods and materials exist, such as bolting or welding of steel plates to the girder end area. However, recently Carbon Fiber Reinforced Polymer (CFRP) has been widely studied and used as an effective material for increasing the shear strength of the web plate in steel girder ends. However, the conventional approach of covering the entire web area with CFRP can be costly and excessively conservative. To efficiently increase shear buckling strength, this research aimed to determine the suitable area for CFRP coverage on the web plate along with the impact of CFRP application direction and the effect of attaching CFRP only to the web center. Through adopting an experimental approach, the study tested eight specimens, and the CFRP was applied in two distinct patterns to tension and compression directions. Furthermore, as for the CFRP coverage area, initially, the whole web area was covered with CFRP, and subsequently, the CFRP coverage area was parametrically reduced. The findings indicate that covering around 40% of the web area by CFRP can produce similar results as CFRP covering the whole web area. Additionally, it was found that the web and CFRP act as a unified composite section until the initiation of shear buckling, making the direction of CFRP application insignificant.

Buckling and ultimate resistance of double-corrugated steel plates under in-plane shear load

The double-corrugated steel plate (DCSP) is a new type of structural member which is fabricated by cold-formed steel materials. It provides better stability and higher shear resistance than conventional single-corrugated steel plate (SCSP). Shear walls with DCSP infilled (D-CSPSWs) have good application potential in high-rise structures. Up to now, studies on D-CSPSWs are still limited and more research work is needed to determine the strength of DCSP. This paper presents a study on the shear buckling and ultimate strength of DCSP. Previous experiments were briefly summarized first to provide useful data for the verification of the subsequent analytical results. Then a reliable FE model of DCSP was established and carefully validated. By combining theoretical studies, numerical simulations and extensive parameter analyses, the buckling strength and ultimate shear strength of DCSP were revealed and corresponding prediction methods were developed. It is found that the local buckling stress of DCSP is mainly affected by the ratio of the plate’s thickness to the maximum width of subpanels. The global buckling stress of DCSP is greatly related to the connecting bolt’s spacings. The theoretical formulae of the elastic local buckling and global buckling strength were developed by considering the realistic boundary condition of the subpanels and introducing the enhancement coefficient, respectively. Corrugation height, plate thickness and bolt density have considerable influence on the ultimate shear strength. A prediction method is proposed and it can provide reasonable and conservative predictions for the ultimate shear strength of DCSP.

Comparative analysis of fire-adapted models for the shear buckling strength of web-posts in castellated steel beams

Web-post buckling by shear is one of the typical failure modes of beams with sequential web openings, as well as the preponderant failure mode in fire. With the increase of the temperature, the modulus of elasticity of steel reduces faster than its resistance, so the beam becomes more susceptible to failure due to instability. This paper presents a comparison between existing formulations for determining the shear buckling strength of web-posts and validated numerical results. The objective was to assess if they are valid in fire conditions, with the modification of the modulus of elasticity and yield strength of steel according to each temperature considered in the analysis, using the statistical evaluation method present in EN 1990:2002. It was evident that the formulations analyzed are satisfactory at ambient temperature but most of them need adjustments when applied in fire.

Shear buckling coefficients of web panels for composite girders considering flange-web stiffness ratio

Designing a web panel for composite girders necessitates an accurate evaluation of the shear buckling strength. However, the current design specifications calculate the strength of web panels for composite girders conservatively. Additionally, its rational determination is missing in existing studies. This study investigates the shear buckling coefficients of composite girders through numerical analysis. The numerical analysis model assumes that the concrete slab fully restrains the web panel. In addition, the concrete slab of the composite girders in the numerical analysis model is replaced by equivalent top flange sections using a transformed thickness according to the modular ratio (n) of the concrete and steel. Additionally, the stiffness of the bottom flange and web panel is parameterized to evaluate the effect of their relative stiffness on the critical shear buckling strength of the web panel. The results show that the relative stiffness of the flange and web panel significantly affects the shear buckling coefficient. To determine the shear buckling coefficient by reflecting these structural characteristics, the relative stiffness is defined as the ratio of the torsional stiffness of the flange to the flexural stiffness of the web panel. The proposed formulas for the shear buckling coefficient of web panels for composite girders correlate well with the numerical analysis results. Since the accurate shear buckling strength can be derived from these formulas, the web panel for composite girders can be designed more accurately and economically.

Analysis of shear buckling for sinusoidal corrugated web beam

Corrugated web beams are increasingly being used owing to their light weight and stability against shear buckling. The modes of shear buckling strength are divided into three categories according to industrial standards: local, global, and interactive. The failure of a corrugated web beam occurs due to material yielding or geometrical buckling. This article presents a parametric sensitivity analysis of the design variables of sinusoidally corrugated steel webs in terms of the shear buckling stress. Because the shear buckling performance of a corrugated web is a function of geometric parameters, the elastic buckling performance was investigated via a parametric study by varying design variables. The shear buckling stress and failure mode were obtained via a buckling analysis. Based on the 486 cases considered during the parametric analysis, the relationship between the shear buckling strength and design variables was verified using polynomial regression models.

Study on shear buckling strength of curved corrugated steel webs for bridges

Study on shear buckling strength of curved corrugated steel webs for bridges

Analysis of the Shear Buckling Strength of Variable-Section Corrugated Steel Webs

Though composite box girder bridges with variable-section corrugated steel webs (CSWs) have been constructed worldwide, their shear behavior has seldom been investigated. This study accordingly analyzed the parameters affecting the elastic shear buckling strength of variable-section CSWs using a finite element analysis (FEA) of the Nanzhao Huaihe Bridge as a case study. The existing formulas for calculating the shear buckling strength of prismatic CSWs were first shown to be inapplicable when the web height exceeded 4,000 mm; alternative formulas were therefore derived and verified to provide suitable accuracy. New formulas were then proposed to calculate the shear buckling strength of variable-section CSWs, and their results exhibited good agreement with those from the FEA. The findings of this study indicate that the boundary conditions have insignificant effect on the calculated buckling strength of different types of variable-section CSWs, as their shear strengths differed by less than 5% under simple and fixed boundary conditions. The results of this study provide an important reference for the design of variable-section CSW bridges.

Modified strip model for indirect buckling restrained shear panel dampers

The indirect buckling restrained shear panel damper (IBRSPD) comprises stiffeners and energy dissipation units that are processed from a hot-rolled H-beam. Under shear loading, the web plates of the units induce a stable energy dissipation capacity to resist earthquakes, and the stiffeners can effectively limit the buckling of the web panels. Then, the partial tension field (PTF) is generated in the web plates owing to the indirect buckling restraint, which leads to the free boundary condition in the vertical edges. This mechanism has not been considered in previous models of the shear panel damper (SPD). In this study, a modified strip (MS) model is proposed to characterize the web plate behavior, and equations for the inclination angle of the PTF action are presented. According to the development degree of the PTF area, four stages are determined, and the components of the shear strength, namely, the shear buckling strength (SBS) and the PTF action, are calculated for each stage. Through monotonic analyses, a comparison between the finite element model and the MS model is conducted to verify the validation of the newly proposed model. In addition, the contributions of the SBS and PTF components are analyzed under cyclic loading while considering the loading history and the pinching effect. With respect to the energy dissipation capacity, the height of the IBRSPD is discussed in relation to the energy dissipation efficiency. Finally, the MS model is adopted in a seismic analysis to investigate the reduction of the seismic response.

Numerical investigation on ultimate shear strength of long steel plate girder web panels at high temperatures

In this article, elastic shear buckling and ultimate shear strength of long steel plate girder web panels subjected to pure shear loading are investigated at both ambient and elevated temperatures by the finite element method (FEM). Ninety-six plate girders with compact, non-compact and slender long web panels are numerically analyzed and compared. From linear eigenvalue analysis, it is shown that AISC 360-16 predictions are more conservative than FEM results such that the difference is about 40% for all ranges of web panel slenderness. According to nonlinear analysis results at ambient temperature, there must be reduction factors applied to AISC 360-16 non-conservative predictions for considering the strength degradation caused by large slenderness values and effects due to initial geometrical imperfection. Furthermore, it is observed that the adopted equation of AISC 360-16 for fire situations yields values that are more non-conservative such that the difference reaches almost 18%. In this regard, the FEM results are used to develop a new equation for predicting the ultimate shear strength of long web panels by taking into account strength degradation caused by large slenderness values, high temperature and initial geometrical imperfections.

NUMERICAL STUDY OF STRENGTHENED SLENDER I‐GIRDERS WITH FIBER REINFORCED POLYMERS

AbstractThis study demonstrates the feasibility of applying diagonal reinforcements composed by fiber reinforced polymers (FRP) on the web surface of slender steel I‐girders. The use of such reinforcements contributes to a higher shear buckling strength capacity of the beam panels. This strengthening technique was evaluated by means of numerical analysis using the finite element software Abaqus®. In the analyzed models the connection between the reinforcement of composite material and the beam was made by structural adhesives. Additionally, beams with traditional diagonal reinforcements made of welded steel plate were simulated for comparison purposes, as well as another model without any diagonal reinforcement.

Experimental study and numerical simulation of replaceable corrugated steel plate-concrete composite shear walls

In this paper, a new structural form of installing a replaceable corner tension-and-compression damper (RCTCD) at the bottom of corrugated steel plate-concrete (CSPC) shear walls was proposed. This new structural wall is called a replaceable corrugated steel plate-concrete (RCSPC) composite shear wall. After a strong earthquake, the damage is mainly concentrated in the RCTCDs, and the function of the structure is quickly restored by replacing the RCTCDs. To study the seismic performance of RCSPC shear walls, cyclic loading tests on one replaceable horizontally corrugated steel plate-concrete (RHCSPC) composite shear wall and one replaceable vertically corrugated steel plate-concrete (RVCSPC) composite shear wall were conducted. To verify the feasibility of replacement, both the RHCSPC and the RVCSPC structural walls experienced replacement and reloading processes. The test results indicate that the structural behaviour of the two structural walls were flexure dominant. The damage in the RCSPC structural walls were mainly concentrated in the RCTCDs. The replacement of the RCTCDs can be implemented conveniently after residual deformation occurs in the structure. Compared with the RHCSPC structural wall, the RVCSPC structural wall had better seismic performance. Subsequently, the experimental and numerical simulation results were compared, the numerical simulation could predict the shear strength of the RVCSPC and RHCSPC shear walls with good accuracy. In addition, simplified formulas were proposed to evaluate the shear buckling strength of the RVCSPC and RHCSPC shear walls. The calculated results agree well with the test results, verifying the accuracy of the proposed formula.

Shear buckling and design strength study of curved girders with corrugated steel webs

Owing to the curvature of curved girders with corrugated steel webs, the inner and outer corrugation angles of the webs are different. For the local buckling behaviour of such webs, under the influence of different parameters, cases of panel lengths ratios were analysed in detail. Results showed that the average value of local buckling coefficients of curved corrugated steel webs was higher than straight ones. Based on Lindner's and El-Metwally's interactive theories, interactive buckling formulas for different panel aspect ratios were given. Additionally, considering the difference between elastic and yielding synthetic indices of curved webs, a buckling design formula was proposed by means of unequal synthetic indices. The finite-element values of local and interactive buckling were designed reasonably, and design parameters were determined through a large amount of analytical data. When the slenderness ratio was less than 1·5, the proposed design curve was found to be better than other available curves. Finally, buckling modes of straight corrugated steel webs in previous experiments were effectively separated by the given judgement formulas of different buckling modes. The percentage of local buckling in the experimental data was found to be highest, which formed a degenerated model compared with the proposed design curve.

Design of Transverse Stiffeners in Plate Girders with Corrugated Web

This study reports investigations into the effect of relative flexural stiffness of intermediate stiffeners γ on the failure zone location in the corrugated web. The study also aimed at obtaining stiffness criterion for intermediate stiffeners that depends on the magnitude of the plate geometry parameter α. To achieve the goals of the study, experimental investigations were conducted into load displacement paths of four exemplary SIN girders. They were simply supported girders, made to full scale, and composed of pre-assembled units. The phenomena occurring in the experiment were represented using the Finite Element Method. For FEM numerical analysis of girders with intermediate stiffeners, models with the web height of 1000, 1250 and 1500 mm, made from 2; 2.5 and 3 mm thick corrugated sheet metal were used. Due to the analysis of 52 girder numerical models, it was possible to propose the stiffness criterion of intermediate stiffeners. The criterion was based on the assessment of shear buckling strength of the corrugated web. Using the regression method, dimensionless coefficients of the stiffener stiffness ks dependent on the optimum stiffness γ were determined. Based on estimated coefficients of the stiffener stiffness ks, the absolute minimum stiffness of intermediate stiffeners Ismin used in corrugated web plate girders was calculated. It was demonstrated that the use of an intermediate stiffener, the stiffness of which is greater than Ismin , additionally leads to a change in the location of the site of the web shear buckling.

Elastic buckling response of rectangular GLARE fiber-metal laminates subjected to shearing stresses

In this article, the elastic buckling response of rectangular GLARE fiber-metal laminates with three different support types subjected to shearing stresses is investigated using the finite element method and eigenvalue buckling analysis. Using validated FEM models, the buckling coefficient-aspect ratio diagrams of eight GLARE grades are obtained and studied along with the diagrams of three UD glass-epoxy composites and monolithic 2024-T3 aluminum. It is found that the critical average buckling stress and the buckling load of the materials increases for increasing metal volume fraction. The effect of the fiber-volume fraction on the shear buckling strength of simply supported and clamped fiber-metal laminates is also studied. It is found that the variation of the fiber-volume fraction has a small influence on the behavior of the buckling coefficient-aspect ratio diagrams of two specific GLARE grades. Furthermore, an approximate method is proposed in order to estimate the new shear buckling strength of a GLARE plate when the fiber-volume fraction changes.

Experimental study on cyclic behavior of composite beam with corrugated steel web considering different shear-span ratio

This paper proposes an innovative use of corrugated steel plates as the webs of the crossbeam in the tower of a suspension bridge to get better seismic performance. Three 1/4-scaled models of composite beam with corrugated steel webs considering different shear-span ratio were fabricated to conduct quasi-static test. The structural behaviors including failure modes, hysteretic curves, ductility, strength and stiffness degradation, energy dissipation capacity, deformation recovery ability, shear force distribution and strain responses were investigated. Test results indicate that the specimen with large shear-span ratio presents ductile flexural failure, and the hysteretic curve is stable and plump with slight pinching, which indicates good energy dissipation performance. However, the specimen with small shear-span ratio fails due to brittle shear buckling of corrugated steel web, showing remarkable pinching phenomenon and poor hysteretic behavior. With the increase of shear-span ratio, the load-carrying capacity and lateral initial stiffness are reduced, but the ductility and energy dissipation ability are improved significantly. The energy dissipation capacity of such composite beam is better than that of the RC structures, the strength degradation is slight for the specimen with a proper shear-span ratio, and the deformation recovery ability is good for all test specimens. The corrugated steel web carries about 80% of the shear force and shear stress uniformly distributed along the web height. The test results demonstrate that the composite beam with corrugated steel web of a reasonable shear-span ratio can be applied in anti-seismic structure with superior energy dissipation performance. In addition, simplified formulas were proposed to evaluate the flexural strength and shear buckling strength of a composite beam with corrugated steel webs, the calculated results agree well with the test results, verifying the accuracy of these proposed formulas.

Numerical simulations on cold-formed steel channels with longitudinally stiffened slotted webs in shear

This paper presents results of a numerical finite element parametric study on elastic shear buckling and ultimate shear strength of cold-formed steel channels with longitudinally stiffened slotted webs. The following parameters were varied: channel height, thickness, flange width, flange lip length, longitudinal stiffener size, perforation pattern, aspect ratio, steel yield stress and boundary conditions. Channels with longitudinally stiffened solid webs subjected to shear load were also studied to provide reference data for comparison with the slotted channels. The parametric study described in this paper allowed us to develop equations for predicting the shear buckling coefficient of longitudinally web stiffened solid channels, as well as equations for predicting the elastic shear buckling load and the ultimate shear strength of channels with longitudinally stiffened slotted webs. The developed shear strength equations without and with tension field action are presented in the paper in the traditional and direct strength method formulations. The developed equations account for the studied parameters and showed good agreements with the finite element simulation results.