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The current design provisions for corrugated steel culverts in North America consider thrust at the springline to be the critical mechanism and location, respectively, when checking capacity. However, experiments have shown that, at shallow cover depths under vehicle loading, the response of these culverts involves both bending moments and thrust forces, and the critical location in terms of capacity is not at the springline. To address this, 3D finite element modeling of the culvert was undertaken using orthotropic shell elements for the corrugated steel structure and continuum elements for a discrete volume of the surrounding soil. The results of an extensive parametric study are used to develop equations for the critical thrust and bending moment under three different vehicle loading configurations. The proposed equations are then compared to the current design code equations in terms of how well they capture the behavior of the finite element model results. The proposed equations are then used to estimate the response of physical experiments conducted in the laboratory and the field and compared to the responses from distributed strain measurements. The equations were found to provide better estimates of thrust and allow the bending moments, which are currently not considered in North American design codes, to be estimated accurately. Limitations of the proposed equations are also discussed. [ABSTRACT FROM AUTHOR]

This article presents a study of the behavior of hybrid steel beams of I-profile cross section subjected to bending. Numerical models of finite elements were developed and validated in the ABAQUS software. In the models, lateral buckling with torsion was disregarded, since the beam will be laterally restrained, so that only local instabilities are present and thus evaluated. Analyses were divided into two stages: first, the elastic buckling analysis was carried out to obtain the critical buckling loads and the buckling modes of the beams; subsequently, analysis of the ultimate strength capacity of the beams was carried out considering residual stresses and initial imperfections. The numerical model was defined and a sensitivity study of the yield strength of the flange steel was carried out. The obtained results from the developed numerical model were satisfactory and, as expected, showed that the hybrid beams resist a greater bending moment effort when compared to their corresponding homogeneous beams. [ABSTRACT FROM AUTHOR]

A new type of precast pile, namely steel strand square piles with reinforcement (PRS), is proposed in present study, which uses steel strand as a prestressed reinforcement and is equipped with hot-rolled reinforcement. Two kinds of full-scale pile specimens with different reinforcement were constructed to study the bending performance by the full-scale tests. The finite element model was also performed to study the differences in bending resistance, deformation capacity, crack resistance, and failure mode because of the reinforcement ratio. The results show that the steel strand in the pile was not pulled off, and the concrete in the compression zone was crushed. The finite element analysis results are close to the results of the full-scale test of the piles, which can simulate the flexural performance of the pile well. The experimental results were closer to the theoretical calculation of the cracking moment. The ultimate bending moment value is about 25% more than the theoretical value. The parametric analysis shows that for the PRS with 0.27% prestressed reinforcement, the best bending performance is achieved with 0.64% non-prestressed reinforcement. For the PRS with 0.64% of non-prestressed reinforcement, the best bending performance is achieved with 0.37% of prestressed reinforcement. [ABSTRACT FROM AUTHOR]

The seismic behaviour of hybrid coupled walls (HCWs) made of a single reinforced concrete (RC) wall connected to two steel side columns through steel links, named as single-pier HCWs (SP-HCWs), is studied through nonlinear finite element simulations. The design concept is that the steel links are intended to work as dissipative elements while the steel side columns and the RC wall should remain elastic. Given that previous studies highlighted difficulties in avoiding damage at the base of the RC wall due to the concentration of bending moment, this study focuses on a special configuration providing very limited damage at the base of the RC wall that could be rapidly and economically repaired. The original scheme of SP-HCW with fixed base is modified introducing a hinged connection combined with vertical steel elements, called corner components. A ductile design methodology is proposed and applied for proportioning 54 case studies with different building heights, coupling ratios, height-to-length ratios of the RC wall, in addition to different base conditions (fixed base, hinged base with corner components designed as non-dissipative elements, hinged base with corner components designed as dissipative elements). Results of nonlinear finite element analyses validate the design methodology and highlight the potentialities of the proposed solutions, showing the benefits of a hinged base with corner components. • The seismic performance of single-pier steel and concrete hybrid coupled walls is studied. • Focus is made on alternative hinged base solutions to protect the wall from damage. • A seismic ductile design procedure is proposed and applied to a wide set of case studies. • Results provide insights into the benefits of the developed base configurations. [ABSTRACT FROM AUTHOR]

Prestressed, precast concrete piles using High-Strength Steel Strands (PPCPs using HSSS) are a new type of precast pile. Compared with prestressed high-strength concrete (PHC) piles, the adoption of ultra-high-strength concrete and HSSS not only improves the load-bearing capacity, but also enhances the ductility of precast piles. The engineering application of PPCPs using HSSS requires not only a high bearing capacity of the pile segments, but also reliable splicing to ensure cooperation between pile segments. Based on the characteristics of strand anchorage plates, this paper proposes a new combination splice using the clamp ring and welding (Combination Splice). The theoretical analysis and design method of this Combination Splice is introduced. This research gives a thorough investigation into the flexural performance of PPCPs using HSSS with the Combination Splice. The flexural tests of PPCPs using HSSS with the Combination Splice were firstly conducted on eight full-scale pile specimens with three different pile diameters and four different steel reinforcement ratios. The flexural performances are evaluated in terms of crack resistance, flexural capacities, crack distribution, as well as strain development. The results indicate that the Combination Splice remain safe and intact when the piles reach the ultimate bending capacity. The ultimate bending moment of tested specimens with the Combination Splice is, on average, 10% larger than that of specimens using a theoretical formula. In light of the experimental data, a finite element analysis (FEA) model has been created to simulate the flexural performance of the piles with the Combination Splice. The FEA results show that the load–displacement curves and crack distribution regions are in good agreement with the experimental findings, which verifies the reliability and accuracy of the FEA model. The parameter analysis investigates the effects of the assembly gap and clamp ring corrosion on the flexural performance of PPCPs using HSSS. The results show that assembly gaps have a greater influence on the flexural capacity and deformation, while the influence of the clamp ring corrosion is negligible, indicating that the Combination Splice has certain advantages in terms of durability. [ABSTRACT FROM AUTHOR]

Traditional beam--column connection structures fail to meet design requirements of hidden beams and columns in the application of composite frames formed by U-shaped steel composite beams (USCBs) and concrete-filled square steel tubular columns (CFSTBCs) to residential buildings. Therefore, a novel beam--column connection structure of U-shaped steel composite beams and concrete-filled steel tubular columns based on channel steel connections was proposed in this study. An experimental study and finite element simulation analysis of the joint performance of the novel composite frame side joint specimen under monotonic load were carried out. Failure mode and bearing capacity of joints under negative bending moment were discussed based on the experimental investigation of two full-scale joints. The influence of beam section height, width--thickness ratio of column, and axial compression ratio on the bearing capacity of joints was explored by analyzing parameters of the finite element model. Results demonstrate that failure form of the joint is tensile crack of concrete floor at flange of core area of the joint under the action of negative bending moment, ductility coefficient of the joint is greater than 2.0, and bearing and ductility performance is excellent. Beam section height significantly influences the bearing capacity of joints, while the width--thickness ratio of the steel tube column slightly influences the bearing capacity of joints when the requirement of "strong columns and weak beams" is met. The bearing capacity of the joint is minimally affected by the change of axial compression ratio when the axial compression ratio of the column is less than or equal to 0.6. However, the bearing capacity is significantly reduced with the increase of the axial compression ratio when the axial compression ratio is greater than 0.6. This study can provide a theoretical basis for the engineering application and popularization of the novel composite frame beam--column connection structure. [ABSTRACT FROM AUTHOR]

In this study, a fully precast steel—ultrahigh performance concrete (UHPC) lightweight composite bridge (LWCB) was proposed based on Mapu Bridge, aiming at accelerating construction in bridge engineering. Cast-in-place joints are generally the controlling factor of segmental structures. Therefore, an innovative girder-to-girder joint that is suitable for LWCB was developed. A specimen consisting of two prefabricated steel—UHPC composite girder parts and one post-cast joint part was fabricated to determine if the joint can effectively transfer load between girders. The flexural behavior of the specimen under a negative bending moment was explored. Finite element analyses of Mapu Bridge showed that the nominal stress of critical sections could meet the required stress, indicating that the design is reasonable. The fatigue performance of the UHPC deck was assessed based on past research, and results revealed that the fatigue performance could meet the design requirements. Based on the test results, a crack width prediction method for the joint interface, a simplified calculation method for the design moment, and a deflection calculation method for the steel—UHPC composite girder in consideration of the UHPC tensile stiffness effect were presented. Good agreements were achieved between the predicted values and test results. [ABSTRACT FROM AUTHOR]

This paper presented a series of tests to investigate the behaviour of the extended end-plate connection utilizing high strength Q960 steel. A total of 8 specimens were tested, including two under ambient temperature and three under high temperature. The results of the tests indicated that increasing the end-plate thickness from 8 mm to 12 mm significantly enhances the flexural capacity and initial rotational stiffness of the connections but reduces the critical temperature and ultimate rotation. In addition, a higher beam bending moment ratio was found to increase the ultimate rotation of the connections while having minimal impact on the critical temperature. Then, the finite element model of the connections was established to investigate the parametric effect, including column axial pressure ratio, beam bending moment ratio, and end-plate thickness on fire resistance. The numerical analysis indicated that increased column axial pressure ratio and end-plate thickness decreased fire endurance, critical temperature, and ultimate rotation of the connections. On the other hand, increasing the beam-bending moment ratio enhanced the ultimate rotation of the connections. Lastly, a rotation-temperature relationship model was proposed to accurately predict the temperature-rotation curve of high-strength steel Q960 end-plate connections, which was validated with experimental data. • Fire tests on response of high strength Q960 steel connections were carried out. • Numerical models were developed to simulate the behaviour of Q960 teel connections at elevated temperatures. • Parametric studies were performed to investigate the effect of key factors on fire resistance of the connections. • A rotation-temperature relationship model was proposed to predict the fire behaviour of Q960 steel connections. [ABSTRACT FROM AUTHOR]

Featured Application: The research results included in the paper can be widely used in designing thin-walled steel elements for use in construction. The use of the presented calculation model for the calculation of continuous beams allows for more optimal and economical design of sections of this element class under resistance conditions. In this model, the real behavior of thin-walled beams under load was taken into account much more precisely in relation to the Eurocode. This made it possible to use the resistance reserves resulting from the effect of longitudinal stress variation and the elastic restraint of the thin-walled cross-section walls. In modern steel construction, thin-walled elements with Class 4 cross-sections are commonly used. For the sake of the computation of such elements according to European Eurocode 3 (EC3), simplified computational models are applied. These models do not account for important parameters that affect the behavior of a structure susceptible to local stability loss. This study discussed the effect of local buckling on the design ultimate resistance of a continuous beam with a thin-walled Class 4 I-shaped cross-section. In the investigations, a more accurate computational model was employed. A new calculation model was proposed, based on the analysis of local buckling separately for the span segment and the support segment of the first span, which are characterized by different distributions of bending moments. Critical stress was determined using the critical plate method (CPM), taking into account the effect of the mutual elastic restraint of the cross-section walls. The stability analysis also accounted for the effect of longitudinal stress variation resulting from the varied distribution of bending moments along the continuous beam length. The results of the calculations were compared with the numerical simulations using the finite element method. The obtained results showed very good congruence. The phenomena mentioned above are not taken into consideration in the computational model provided in EC3. Based on the critical stress calculated as above, "local" critical moments were determined. These constitute a limit on the validity of the Vlasov theory of thin-walled bars. Design ultimate resistance of the I-shaped cross-section was determined from the plastic yield condition of the most compressed edge under the assumptions specified in the study. Detailed calculations were performed for I-sections welded from thin metal sheets, and for sections made from two cold-formed channels (2C). The impact of the following factors on the critical resistance and design ultimate resistance of the midspan and support cross-sections was analyzed: (1) longitudinal stress variation, (2) relative plate slenderness of the flange, and (3) span length of the continuous beam. The results were compared with the outcomes obtained for box sections with the same contour dimensions, and also with those produced acc. EC3. It was shown that compared with calculations acc. EC3, those performed in accordance with the CPM described much more accurately the behavior of the uniformly loaded continuous beam with a thin-walled section. This could lead to a more effective design of structures of this class. [ABSTRACT FROM AUTHOR]

This paper presents an evaluation of the design rules for the bending moment–shear force (M − V) interaction of cold- and hot-formed square, and rectangular hollow steel sections (SHS & RHS). More specifically, the design rules, as provided by EN1993-1-1 regarding RHS and SHS of section class 1 and 2 are covered for the steel grades S235 up to and including S460. A 4-point bending test was simulated by means of a finite element model, which was validated on the basis of experimental tests from existing literature. A parametric study was performed and numerical M − V interaction results were compared to the provisions in EN1993-1-1. This comparison indicates that the current design rules in EN1993-1-1 regarding M − V interaction are conservative and overestimate the reduction of the bending resistance due to the presence of shear. Alternative design rules for the shear area and M − V interaction of RHS and SHS are proposed and evaluated by means of a statistical assessment procedure based on existing literature and EN1990-1-1. Both newly developed design rules are shown to ensure an adequate reliability level when a partial safety factor equal to 1 is used. • Evaluation of the design rules for the M − V interaction of RHS and SHS. • An alternative design rule is proposed. • The proposed shear area matches the numerical results for all tested sections. [ABSTRACT FROM AUTHOR]

This paper aims to experimentally and numerically investigate the structural performance of speed-lock joints with split bolts in steel storage racks. There are no bolts in the typical speed-lock joint for its ease of installation, and the joint transmits and bears force through interactions of the tabs and upright beam holes. However, the joint under seismic loading shows large looseness and slippage with low stiffness. Also, the energy dissipation capacity is insufficient and the failure of tabs in the joints might lead to brittle behavior. In this study, new detail of the speed-lock joint with bolts is proposed by adding a pair of split bolts in the beam end plate while still preserving its merit of ease of installation. A double-cantilever beam test was designed to test this speed-lock joint with split bolts along with the typical speed-lock joint. Low cyclic loading tests were performed on both types of joints: with split bolts and without split bolts. The results revealed the benefits that the split bolts could bring to significantly enhance the performance of the joint in terms of the maximum bending moment, the initial stiffness, the displacement ductility coefficient, the equivalent viscous damping coefficient, and the energy consumption. In addition, a two-step analysis method was proposed for the high-fidelity finite element model of the joints to overcome the complex contact nonlinearity. The numerical model was then validated with the tests for further numerical studies on the performance of speed lock joints with/without bolts. • Experimental tests were designed and conducted on the typical speed-lock joint and proposed joint with added split bolts. • With split bolts, the joint has less slippage and looseness and effectively eliminates the brittle tab failure. • Speed-lock joints with split bolts possess an additional load bearing mechanism that improves the seismic performance. • Atwo-step analysis method was proposed for the finite element model of the joints to overcome the complex contact nonlinearity. • Stress distributions from experimental and numerical results reveal the joint's improved bearing mechanism. [ABSTRACT FROM AUTHOR]

The moment gradient factor is an important parameter to be considered in the design of beams subjected to failure by Lateral-torsional Buckling. The analytical formulation to obtain the critical moment for the LTB is based on the assumption of applying a constant bending moment along the free span of the structural element. This loading situation is not usual in engineering projects, so it is necessary to correct the value of the critical moment according to the different loading situations that can be found in practical cases. Thus, many design codes worldwide assign values to perform this correction. The moment gradient factor, Cb, is determined by comparing the elastic critical moment of a beam subject to varying moment condition with that subject to a constant moment condition. When considering beams with web openings, there are currently no recommendations or proposals for calculating the moment gradient factor, considering loads applied outside the shear center. There are also no explicit recommendations in standards regarding the design of this type of structure. Recent research deals with the influence of cellular beam parameters on the moment gradient factor; however, they do not present explicit proposals for its calculation in structures of this nature. The research scenario in the literature becomes even more scarce when considering beams with sinusoidal web openings. Thus, the paper investigates this for a wide range of I-beams with openings, with the goal of analyzing the influence of the openings on the C b , as well as proposing formulae for usual design situations. The proposals were obtained through prediction models derived from an extensive parametric study using the ABAQUS finite element software, in which 34,020 models were developed. • A massive parametric study based on 34,020 finite element models is presented. • The influence of the geometric parameters of beams with sinusoidal web openings in the moment gradient factor was explored. • A new proposal for determining the moment gradient factor in steel I-beams with sinusoidal openings was developed. • The methodology presented is considerably more efficient than the proposals of design codes. [ABSTRACT FROM AUTHOR]

In order to explore the ultimate biaxial bending performance of H-section steel members under different loading conditions, we conduct a comprehensive parametric study on H-section members with different axial force ratios, web and flange width-to-thickness ratios, and loading angles. Material and geometric nonlinearity are considered, and previous laboratory test results validate the finite element models. A criterion for determining the ultimate state of biaxial bending members is proposed based on the elastic–plastic stability theory. The ultimate biaxial capacity of the members subjected to monotonic biaxial bending and axial force is analyzed, and biaxial moment ultimate interaction curves are obtained by least square fitting. Furthermore, the influences of four different hysteretic protocols on the hysteretic behavior of the members are investigated, and the applicability of the monotonic biaxial moment limit interaction curve to the cyclic loading model is verified. A design equation for predicting the ultimate capacity of the members is proposed, considering the hardening effect of the material and the interaction effect of the plate. The proposed approach can predict the ultimate capacity of H-section biaxial bending members. The method is not limited by section classification and loading protocol and has universal applicability. • A criterion for determining the ultimate state of H-shaped steel members subjected to biaxial bending. • The ultimate state development process of H-shaped steel members under monotonic loading. • Four complex cyclic loading systems, including the BL, REC, ROM, CRU, were selected to conduct the ultimate state analysis. • The similarities and differences of ultimate state between monotonic loading and cyclic loading. • Biaxial ultimate interaction curves accurately predict ultimate bidirectional bending moment of members. [ABSTRACT FROM AUTHOR]

In this study, a novel three-dimensional semi-rigid steel joint with a channel steel component is proposed, in which the channel steel component is connected to the column flange through a hybrid connection of bolts and welds along the minor axis. The design of the minor axis connection in this study had no weakening effect on the column web, and it was more convenient and easier to attach the additional channel steel component than the additional plates to the column flanges by welding. In order to investigate the static behaviour and seismic performance of the proposed novel three-dimensional semi-rigid steel joint with a channel steel component and to evaluate the interaction between both axes, numerical analyses were conducted systematically. The finite element (FE) models are firstly calibrated against the experimental results in order to get accurate results, and then the rotating characteristics, joint moment capacity, joint stiffness, ductility and energy dissipation capacity of the proposed novel semi-rigid steel joints were analysed under ten loading cases along the major and minor axes. The results indicate that the proposed novel semi-rigid steel joint has good energy dissipation capacity and deformation performance. Loading in the major-axis direction has almost no influence on the ultimate joint moment capacity but has some influence on the initial stiffness, ductility, stiffness degradation and energy dissipation ability of the proposed novel semi-rigid steel joint along the minor axis. In addition, the modified moment-rotation (M - θ) hysteretic model for the proposed novel semi-rigid steel joint is capable of effectively characterising its hysteretic behaviours, which can provide a reference for practical applications. • A novel 3D semi-rigid steel joint with channel steel component is proposed. • It is simpler and easier to attach channel steel component in minor-axis direction. • The novel joint has a good energy dissipation capacity and deformation performance. • Loading in major axis has some influence on the mechanical behaviours in minor axis. • The modified M - θ hysteretic model for the proposed novel joint is proposed. [ABSTRACT FROM AUTHOR]

Steel transmission poles are widely used for their strength, ease of construction, small footprint, and aesthetic appearance. These poles can be either directly embedded into their foundations or supported on based plates which are connected to the reinforced concrete footings via group of anchor bolts. There are few available published methods for the analysis and design of this type of base plate connection. These methods are not widely used in the industry as they are either complex, lack solid theoretical background, or yield results that are not consistent with manufacturer's time-tested proprietary design methods. Therefore, there is a need for an accurate method suitable for technical or design office for designing these connections when subjected to axial loads, bending moments or the combined effect of both. This paper presents a numerical study performed on the base plates of polygonal steel poles that are supported directly on anchor bolts with levelling nuts and subjected to bending moment and axial load. The Finite Element (FE) analysis part of the work is carried out using ADINA software and the results obtained from the analyses are compared with published experimental results from which it is concluded that the finite element model can accurately predict the behaviour of these connections. Parametric investigation is then conducted to gain more insight into the behaviour of these base plate connections and to use the obtained data the validation of the proposed design method. The parametric investigation covered the behaviour of these connections under pure axial load and pure bending moment while the varying parameters considered included number of shaft sides, base plate thickness, number of anchor bolts and anchor bolt diameter. Design formulae based on the yield line theory are then proposed and a comparison between the yield loads calculated using the proposed expressions and finite element results is presented. The yield loads resulting from using the proposed design method agreed with the finite element results with a maximum calculated difference of 13%. [ABSTRACT FROM AUTHOR]

Open cross sections are used in structural applications to resist bending moments. The buckling length specified in the current standards and specifications was firstly defined by Nethercot [13] and covered only doubly symmetric I-sections. In this research, a theoretical program was performed to study the elastic and inelastic behavior of overhanging C-section beams bent about the major axis. A finite element model, correlated well with experimental results, was used in this study to perform a parametric study. Nonlinear geometrical and material analyses were incorporated in the model. Four types of lateral supports at the tip of the overhanging beams were studied. The effect of different boundary conditions at the root (intermediate support) of the overhanging beams was studied. Only concentrated load at the tip was considered. Three different loading positions, with respect to cross-section height, were studied. Based on the parametric study, proposed design model, taking into consideration the effect of different parameters on the ultimate moment capacity of such beams, was presented. Modified effective buckling lengths of such beams were compared to those suggested by SSRC Guide [8], which were incorporated in most current standards and specifications. This comparison showed that the ultimate moment capacities of such beams computed according to AISC Specification [1], BS5950 [3], Eurocode3 [7] and ECP [5] varied from overconservative up to 85% to unconservative up to 15%, depending on the overhanging length, back span length, boundary conditions and the load location along the beam depth. [ABSTRACT FROM AUTHOR]

This study explored the impact of irregular dynamic loads on castellated steel beams (CSBs) by conducting drop weight impact tests and establishing a numerical model using the nonlinear finite element method. The numerical simulation results were compared with the test results of the impact to verify its validity and analyze the buckling process and stress development of the CSB under impact load. Results showed that during the impact process, the maximum shear force was achieved first, followed by maximum bending moment and maximum deflection, respectively. It was observed that the increase in impact velocity and impact mass were unfavorable to the deflection of the CSBs, and resulted in an increase in the time required to dissipate impact energy. Furthermore, the ratio of spacing between openings to beam height exhibited a minor impact on the deflection in the range of 1.083–1.75. The ratio of opening height to beam height mainly affected the deflection near the midspan of the CSBs in the range of 0.5–0.7. The impact location significantly influenced the shape of the deflection curve. The larger the span-height ratio was, the more unfavorable it was for the CSBs to resist the impact. In addition, while the clamped support boundary condition reduced CSB deflection, it resulted in a rather substantial bending moment at the CSB ends. Based on the support rotation value as the damage evaluation index, a damage assessment curve with impact velocity and impact mass as the main control parameters was established. • The impact of irregular dynamic loads on castellated steel beams (CSBs) was explored by FE method. • The proposed numerical model could simulate the dynamic response of CSBs under the impact load. • A parameter analysis was determined the influential factors of the CSBs under impact load. [ABSTRACT FROM AUTHOR]

Control of continuous chips in turning operation is a very vital issue to enhance productivity and operator safety. A famous method to control the chip size is utilization of chip breaker. In this study, the influence of different aspects of chip breaker geometry on cutting force, chip shape, and bending moment was evaluated by using finite element and experimental approaches. Therefore, cutting tests were carried out on AISI 1045 steel using tungsten carbide inserts with various chip breaker geometries. The results indicated that the predicted cutting force and chip shape are in close agreement with the experimental ones. It is also observed that the bending moment generated by the upper level of breadth surface has the highest contribution in the development of combined and nonuniform state of stress at the root and body of deformed chip. Meanwhile, the chip breaker geometry had a significant effect on the cutting force value. [ABSTRACT FROM AUTHOR]

T-stubs are generally used to represent the tension zone of bolted moment resisting connections. The bolts are considered at present as components loaded only in tension. This paper investigates the influence of the bolt bending on the behavior of the T-stubs. A 3D finite element model was first developed and validated by comparison with experimental results found in the literature. The numerical model was then used to analyse the behavior of various T-stubs regarding mainly the values of the axial tensile forces and the bending moments in the bolts. The results show the influence of the bolt bending moment on the failure mode of some T-stubs. The numerical model was also used to evaluate the accuracy of the analytical interaction formula determining the resistance of isolated bolts subjected to bending moment and axial tensile force. Finally, an analytical model is proposed to evaluate the bending moments and the axial tensile forces in the bolts considered as T-stub components. The comparisons with the numerical model results show that the analytical model represents well the behavior of T-stubs considering the bending moments in the bolts. [ABSTRACT FROM AUTHOR]

A novel type of SPDs with bent web panels (BSPDs) is developed, in which the end plate of the BSPD is connected to the web of the composite beam. In this configuration, the bending moment resulting from the SPDs can be minimized, thereby reducing the damage to the concrete slab. In this study, twelve specimens were designed and tested under quasi-static hysteretic loading to investigate the influence of web thickness, constrained flange, out-of-plane buckling restraint, and BSPD length ratio on the mechanical properties of BSPDs. Furthermore, the failure modes and hysteretic force–displacement curves of BSPDs made of low-yield-point steel are obtained through the tests. Based on the results, the effects of design parameters on stiffness, shear strength, deformation capacity, overstrength factor, and energy dissipation capacity of BSPDs were analyzed. The excellent mechanical properties of the low-yield-point steel enabled the BSPD to yield in lower strength and dissipate energy at a larger deformation. Moreover, introducing the constrained flange and reducing the BSPD length ratio can further improve the seismic performance of the BSPD. Finally, finite element models were established to simulate the cyclic behavior of BSPDs. [Display omitted] • A novel type of Shear Panel Dampers with bent web (BSPDs)are proposed to alleviate the damage of the concrete slab. • The seismic performance of the BSPDs are verified with experiments. • Key parameters on the BSPDs performance are analyzed based on the experiment results. • The proposed shear strength formula in the code is modified based on the experiment results. • Finite element models are established to simulate the complex mechanical properties of the BSPDs. Shear panel dampers (SPDs) are widely used in eccentrically braced composite frames (EBCFs) to effectively increase their stiffness and strength and dissipate input energy through plastic deformation in seismic conditions. However, these vertically installed SPDs could also impose an additional bending moment and axial forces on the composite beam in the frame, thus damaging the concrete slab of the frame. The SPDs used in this study were bent in the middle and connected to the web of the composite beam in the frame to overcome the drawbacks of traditional SPDs. Therefore, the resulted bending moment and axial force by the SPDs can be minimized, thus controlling the damage to the concrete slab. In this study, the cyclic behavior of the bent SPDs (BSPDs) made of low-yield-point steel is experimentally studied. Twelve specimens were designed and tested under quasi-static hysteretic loading to investigate the influence of web thickness, constrained flange, out-of-plane buckling restraint, and BSPD length ratio on the mechanical properties of BSPDs. Furthermore, the failure modes and hysteretic force–displacement curves of BSPDs made of low-yield-point steel are obtained through the tests. Finally, finite element models were established to simulate the cyclic behavior of BSPDs and analyze the key factors affecting the mechanical properties of BSPDs. [ABSTRACT FROM AUTHOR]

A family of interaction expressions are developed for steel elliptical hollow sections (EHSs) subjected to combinations of axial force, biaxial bending moments, torsion, and bimoments. The formulation is based on kinematically admissible strain fields within the context of the upper bound theorem of plasticity. The interaction relations derived successfully capture the effect of confining radial strains present at welded end sections, as well as sections that are free to deform in the radial direction away from end welded sections. The interaction expressions developed consist of a set of elliptical integrals which are cast in a dimensionless form applicable for EHS of general geometries. An iterative solution technique is developed to solve the resulting nonlinear relations. The applicability of the resulting interaction relations for conducting the cross-sectional check is illustrated through examples. A comparison with shell finite-element analysis results illustrates the validity of the interaction relations derived. [ABSTRACT FROM AUTHOR]

Abstract: This is part one of a two-part paper reporting the results of an investigation into the characteristics of catenary action and their effect on structures. In this paper, it is shown that when catenary action occurs, the bending moment will decrease significantly in the beams. It is also demonstrated that when a column is destroyed by a blast, the failure strain will be reached at the simple beam-to-column joint. To enhance the survival capability of the steel framed structures subjected to a terrorist blast, novel retrofitting schemes are proposed in this paper for strengthening the simple joints of existing tall steel framed structures by changing the partial-strength shear-resisting joints to the full-strength moment-resisting joints, ensuring the full development of catenary action. To support the above mentioned viewpoints, the catenary behavior of a truss model is evaluated and exact results are given. In the subsequent companion paper, these views are also corroborated by means of finite element analysis. [Copyright &y& Elsevier]

This paper presents a study on the strength and behavior of cold-formed steel Z-sections with simple and complex stiffeners subjected to major axis bending. The study involved both experimental and numerical investigations, in which a series of specimens were examined. All specimens were failed by the combined mode of shear and moment. The results from the investigations were analyzed and compared with the combined moment and shear strengths predicted by international design rules. The suitability of the design rules in predicting the combined capacity of Z-section with complex stiffeners was assessed through a reliability analysis. [ABSTRACT FROM AUTHOR]