Infill Steel Research Articles

Experimental Study of Composite Steel Plate Shear Wall with Flush End-Plate Connection

This paper presents an investigation on the structural performance of steel plate shear wall (SPSW) with flush end-plate beam–column connections and infill precast reinforced concrete (precast RC) panels. Two single-span two-story SPSW specimens, including unstiffened SPSW (NBRP) and precast RC panel restrained SPSW (Con-BRP), are first tested, followed with a parametric study by finite element method. Precast RC cover panels are installed on both sides of the infill steel plate and are disconnected from steel frame. Test results indicate that the use of precast RC cover panels increases the load carrying and energy dissipation capacities of the SPSW structure, but decreases its ductility. It is also effective in reducing the inward flexural deformation of columns. Moreover, the stiffening effect of the infill steel plate on the beam–column connections remains, which is a result of the precast RC cover panel’s resistance to the local buckling and the tears of the infill steel plates. The influence of the gap size between the precast RC cover plate and frame members on the failure mode of the specimen Con-BRP is also investigated, based on which a maximum gap size is recommended. Conclusions are drawn that SPSW structure with flush end-plate beam–column connections and precast RC cover panels fully exploits the strength of infill steel plates and exhibits excellent structural performance.

Research on steel plate shear walls stiffened with X-shaped restrainers: Hysteretic behavior and effect of height-to-thickness ratio of steel plate

This paper proposed a novel buckling restrained steel plate shear wall (simply referred to as XSPSW) composed of X-shaped restrainers, an infill steel plate, and boundary restrainers. The X-shaped restrainers are placed on both sides of the infill steel plate, and the infill steel plate is divided into a series of diagonally arranged square subplates with a small height-to-thickness ratio. The X-shaped restrainers can effectively restrain the shear bucking of the infill steel plate and improve the seismic energy dissipation capacity of the shear wall. A refined numerical analysis model of the unstiffened steel plate shear wall (USPSW) and XSPSW was established and the validity of the model was verified by experiment. Numerical analysis was conducted to investigate the force mechanism and hysteretic behavior of the XSPSW. The results demonstrate that the mechanical behavior of the XSPSW is controlled by the square subplate. Compared to the USPSW, the shear buckling capacity, peak load, and energy dissipation capacity of the XSPSW are higher by at least 17%, 5%, and 7%, respectively, and the constraint efficiency of the out-of-plane displacement is larger than 55%. With the decrease in the height-to-thickness ratio of the subplate, the improvements in the shear buckling capacity, peak load, and energy dissipation capacity are increased to 29%, 31%, and 20%, respectively. Moreover, the constraint efficiency of the out-of-plane displacement rises to 92%, and the hysteretic curve tends to be full. The influence of the height-to-thickness ratio of the infill steel plate on the bearing capacity and energy dissipation capacity of the XSPSW is less than 2.5% and 1.2%, respectively.

Experimental and Numerical Investigation of Steel Beam-to-CFST Column Frame-Thin Steel Plate Shear Walls with Cross Stiffness

Steel plate shear wall (SPSW) systems have been used increasingly in medium- and high-rise buildings in recent decades. Two major issues in the slender-web SPSW are the buckling of H-section steel column base and significant pinching in hysteretic curves. As a solution, SPSW using concrete-filled steel tubular (CFST) column and cross stiffeners was proposed in this paper. Cyclic tests of two specimens of 1/3 scaled steel beam-to-CFST column frame-thin SPSW with cross stiffeners or without stiffeners were conducted. Based on the verified finite element method, parametric investigations considering the effect of the flexural rigidity of CFST column, width-to-height aspect ratio, height-to-thickness ratio of infill steel plate and relative rigidity of cross stiffener were carried out. Findings show that SPSW using CFST column exhibited favorable ductility behavior with no sudden loss of lateral bearing capacity. Adding stiffeners to SPSWs relieves the pinching effect of hysteretic curves and reduces the maximum lateral displacement substantially. With stiffeners, the average yield load and the peak load of SPSWs were approximately 15% and 9% higher than that of the unstiffened specimens. Moreover, a flexural rigidity of CFST column of at least 2.5 and a stiffener rigidity of 30–50 were recommended to provide an economical and approving lateral bearing capacity.

Steel–concrete composite shear walls using precast high performance fiber reinforced concrete panels

SummaryIn this research, seismic performance of composite steel plate shear walls (CSPSWs) using high performance fiber reinforced concrete (HPFRC) panels is experimentally and numerically investigated. Three one‐story one‐bay CSPSW specimens using precast HPFRC panels were designed and fabricated for cyclic quasi‐static experiments. The HPFRC panels of composite shear wall specimens did not have any steel rebars. The main purpose of the study was to understand the effects of rigid and semirigid HPFRC panels on the seismic behavior of the system. Shear capacity, ultimate shear strength, lateral stiffness, energy dissipation, and ductility ratios of the specimens are evaluated.The experimental results demonstrate that specimens were able to resist lateral load up to at least interstory drift of 6%. Using HPFRC panels, CSPSW specimens becomes stiffer in the elastic region, and the yield displacement of the shear wall is decreased; therefore, the ductility ratio of the system is increased. It should be noted that ultimate shear strength, initial elastic stiffness, and energy absorption of specimens with an HPFRC panel on one side or both sides of the infill steel plate were approximately the same. However, using two HPFRC panels is not economical in comparison with CSPSW with an HPFRC panel on one side. Additionally, the second panel increases the seismic mass of the structure.

Improved steel frame performance against progressive collapse with infill panels

Local failure of one or more components due to abnormal loading can induce progressive collapse of a building structure. Herein, improved structural robustness is targeted to improve steel frame performance against progressive collapse. A multi-scale analysis model is constructed; then, the anti-collapse performance of a plane steel frame structure with a flush end plate connection is comprehensively analyzed using nonlinear static analysis. To enhance the anti-collapse capability of the steel frame structure, reasonable addition of infill panels in indirect- and direct-influence areas is proposed. Infill panels properly arranged in direct influence area can give full play to the Vierendeel mechanism, and effectively improve combined ability of the remaining structure. And then 1/8–1/6 of the net span is recommended as the length of the infill steel panel for the steel frame structure with flush end plate connection.

Study on Seismic Performance and Damage Analysis of Steel Plate Shear Wall with Partially Encased Composite (PEC) Columns

A steel plate shear wall often uses partially encased composite (PEC) columns instead of edge frame columns. Such a steel plate shear wall not only bears the gravity load of the structure and resists the bending moment caused by lateral force by taking advantage of the high bearing capacity and bending stiffness of PEC columns, but also effectively anchors with the frame column to counteract the tension field generated by the steel plate. Therefore, the performance of the steel plate shear wall after buckling can be fully exerted and the seismic performance of the structure can be improved. In order to investigate the seismic performance of the structure, a 1/3-scale specimen test of steel plate shear wall with PEC columns is designed and fabricated, and a finite element model is established with the same size of test. It is found that the test and simulation results are in good agreement, which confirms the reliability of the simulation. Subsequently, 20 models with different parameters of steel plate shear wall with PEC columns are analyzed using ABAQUS. Finally, the failure mode, hysteretic behavior, skeleton curve, and bearing capacity of steel plate shear wall with PEC columns are obtained. The results show that PEC columns have a good anchoring effect on the diagonal tension field and can fully exert the plasticity of the infill steel plate, so that steel plate shear wall with PEC columns has superior seismic performance. Experiments also reveal that the crack type of damages appear in a steel plate shear wall with PEC columns, and, as a future work, the authors will explore the use of structural health monitoring methods, such as piezoceramic transducer-based method, to monitor such cracks.

Concrete panel thickness demand for the design of composite steel plate shear wall

SummaryComposite steel plate shear walls (C‐SPWs) are composed of an infill steel plate and reinforced concrete encasements. With an adequate thickness, the concrete encasement can effectively prevent the premature buckling of the infill steel plate. Researchers have provided nonconservative concrete thickness demands through analyses of approximate elastic buckling, for which the analytical model is too simplistic to simulate C‐SPW buckling. In this paper, the buckling of C‐SPW is addressed using a nonlinear finite element method. To assist this method, a formula for the buckling strength of C‐SPW is theoretically developed. Utilizing the results of nonlinear finite element analysis on C‐SPW, the effects of concrete panel thickness, concrete elastic modulus, infill steel plate thickness, panel aspect ratio, and stud spacing on the infill steel plate buckling are analyzed, and the critical drift ratio corresponding to the buckling of the infill steel plate is obtained. According to the criterion that the C‐SPW will not buckle until its drift ratio achieves the drift limit (0.4%), the minimum concrete panel thicknesses demands are captured from finite element analysis. Fitting these predicted minimum concrete thicknesses, an available formula is proposed for the concrete thickness demand in the design of C‐SPW.

Characterizing the Cyclic Behavior of Stiffened SPSWs

To enhance the behavior of steel plate shear walls, stiffeners are attached on the infill plate. The various researches on the stiffened Steel Plate Shear Walls (SPSWs) with Low Yield Point (LYP) infill steel plate have approved excellent capacity of this system. In those studies, the researcher focused on the specific type on stiffeners and in some cases, different results was reported. To cover different aspects, to provide comprehensive necessary data for structure designers and, to study the post-buckling and performance factors, this research is conducted. Using the validated Finite Element (FE) models with experimental test results, an analytical study of a single story SPSWs conducted to determine the influence of the selected parameters on the strength, stiffness, energy absorption and seismic performance factors. The variant parameters include the stiffeners pattern, stiffeners thickness, one-side or double-sides stiffeners and the slenderness of the stiffened infill plates. The results showed that cross-stiffened pattern is preferable in the one-side stiffening method while, diagonal pattern in double-side shape. Finally, the value of seismic performance factors is proposed for stiffened SPSWs.

Shear‐displacement diagram of steel plate shear walls with precompression from adjacent frame columns

SummaryAn analytical model of the unstiffened steel plate shear wall (SPSW) considering precompression from the adjacent frame columns is proposed and experimentally verified. First, the distribution and transferring of the gravity loads between boundary columns and the infill steel plate was proposed. Second, the shear‐displacement diagram of the SPSW under compression–shear interaction was obtained, and to further consider the global bending deformation, the shear‐displacement diagram of the SPSW under compression–shear–bending interaction was obtained. Third, the load‐carrying capacities and deformations at the state of elastic buckling of the infill steel plate, the yield of Zones I and III, the yield of Zone II, and the yield of the boundary frame were presented. Finally, cyclic loading test on four scaled one story single bay unstiffened SPSWs under different axial forces at the top of the columns was carried out to verify the proposed analytical model. Shear‐displacement relationship, shear capacity, and envelope curves of the specimens were compared with the predicted values. Results indicate that the proposed analytical model can reasonably predict the decrease of the shear load capacity and stiffness of the SPSWs due to the existence of the axial load at the boundary columns.

Seismic performance of steel plate shear walls with variable column flexural stiffness

Cyclic behaviour of composite (steel - concrete) plate shear walls (CPSW) with variable column flexural stiffness is experimentally and numerically investigated. The investigation included design, fabrication and testing of three pairs of one-bay one-storey CPSW specimens. The reference specimen pair was designed in way that its column flexural stiffness corresponds to the value required by the design codes, while within the other two specimen pairs column flexural stiffness was reduced by 18% and 36%, respectively. Specimens were subjected to quasi-static cyclic tests. Obtained results indicate that column flexural stiffness reduction in CPSW does not have negative impact on the overall behaviour allowing for satisfactory performance for up to 4% storey drift ratio while also enabling inelastic buckling of the infill steel plate. Additionally, in comparison to similar steel plate shear wall (SPSW) specimens, column pull-in deformations are less pronounced within CPSW specimens. Therefore, the results indicate that prescribed minimal column flexural stiffness value used for CPSW might be conservative, and can additionally be reduced when compared to the prescribed value for SPSWs. Furthermore, finite element (FE) pushover simulations were conducted using shell and solid elements. Such FE models can adequately simulate cyclic behaviour of CPSW and as such could be further used for numerical parametric analyses. It is necessary to mention that the implemented pushover FE models were not able to adequately reproduce column pull-in deformation and that further development of FE simulations is required where cyclic loading of the shear walls needs to be simulated.

Experimental Investigation of Steel Plate Shear Walls under Shear‐Compression Interaction

Four scaled one‐storey single‐bay steel plate shear wall (SPSW) specimens with unstiffened panels were tested to determine their behaviour under cyclic loadings. The shear walls had moment‐resisting beam‐to‐column connections. Four different vertical loads, i.e., 300 kN, 600 kN, 900 kN, and 1200 kN, representing the gravity load of the upper storeys were applied at the top of the boundary columns through a force distribution beam. A horizontal cyclic load was then applied at the top of the specimens. The specimen behaviour, envelope curves, axial stress distribution of the infill steel plate, and shear capacity were analyzed. The axial stress distribution and envelope curves were compared with the values predicted using an analytical model available in the literature.

Study of buckling-restrained braces with concrete infilled GFRP tubes

In the proposed buckling-restrained brace (BRB), a concrete infilled glass-fibre reinforced polymer (GFRP) tube is used instead of a conventional concrete infilled steel tube to restrict steel inner core buckling. It has the following advantages: 1) The GFRP is a high-strength and flexible material available for structural components; 2) Its use as an outer constraint material is also a solution for poor corrosion resistance of the outer steel tube; In this study, 11 BRB specimens with concrete infilled GFRP tubes and 3 BRB specimens with concrete infilled steel tubes were designed to investigate the effects of the types of GFRP and constraint ratios on the hysteretic behaviour of the GFRP tube BRBs. The performance of the GFRP tube BRBs was also compared to the steel tube BRBs composed of three different lengths of steel tubes with the same wall thickness. All the GFRP tube BRB specimens had the same rectangular steel inner core and included two types of GFRP tubes with three different lengths and thicknesses. The medium- and long-length filaments winding GFRP tube BRB specimens buckled at the last stage of the test, while global buckling developed the cracks in the middle of the GFRP tube. All other BRB specimens didn’t buckle and underwent the complete loading process without degradation in stiffness and strength. The finite element models of BRBs were built using ABAQUS, considering the constitutive models of the GFRP, steel and concrete subjected to cyclic loading. The finite element model of the GFRP tube BRBs could simulate the performance of the BRBs well, and the results of analysis were calibrated with experimental results. All the BRB specimens exhibited good hysteretic behaviour, sufficient load-bearing capacity, large ductility and energy dissipation capacity. The GFRP tube BRBs may share the same design criteria as the traditional steel tube BRB by limiting their constraint ratios, and the GFRP tube may be used as an alternative to the traditional outer restraining tube especially for those BRBs with strict durability requirement.

Seismic response tests and analytical assessment of blind bolted assembly CFST frames with beam-connected SPSWs

This paper presents a series of experimental and analytical studies to investigate the seismic behavior of blind bolted assembly concrete filled steel tube (CFST) frames with infill steel plate shear walls (SPSWs) connected to beam only. Two specimens of single-bay, two-story blind bolted assembly CFST frames with beam-connected SPSWs were fabricated and tested under lateral cyclic load combined with a constant vertical axial load. The test parameters include the column section type, the beam-SPSW connection type and the SPSW setting. Typical failure modes of the specimens were summarized and discussed. The test results show that the presence of SPSWs can compensate effectively the relatively small lateral stiffness of bare blind bolted CFST frames, and the novel SPSW-frame system exhibited good hysteretic performance, ductility and energy dissipation capacity. Moreover, the moments at the beam ends of a CFST frame with semi-rigid joints under two partial vertical loads resulting from the beam-connected SPSWs are derived. A practical design method for semi-rigid CFST frames with beam-connected SPSWs is summarized for checking the strength of blind bolted end plate joints, steel beams and CFST columns. The accuracy of the design method is also verified by the test results. The study shows that the novel SPSW-frame has good potential for application in earthquake resistant design of steel frame structures.

The Effect of Infill Steel Plate Thickness on the Cycle Behavior of Steel Plate Shear Walls

Steel plate shear wall (SPSW) is commonly used in civil schemes because of its good deformability and stiffness. In this research, the numerical analysis of steel plate shear wall (SPSW) with unstiffened infill steel plate is conducted. This paper explains the effect of thickness variation of infill steel plate on behavior of steel plate. In this status, several samples are designed and checked by rigid frame and actuator. The experimental samples is joined to a rigid frame. 3 numerical specimens consist of steel plate shear wall with different thickness (1.5, 3, 4. 5) mm formed by finite element code which is advanced by the Amirkabir university. To confirm the model, numerical results were discussed with a valid experiment which explain suitable agreement. Numerical model tested under cyclic loading with frequency of 1/60 Hz. Results show that the increase of infill steel plate thickness enhance stiffness and ductility ratio of model. And so, would decrease energy absorption in comparison with the reference model

The Effect of Infill Steel Plate Thickness on the Cycle Behavior of Steel Plate Shear Walls

The effect of changing in the bed slope of stilling basins produces changing in characteristics of the hydraulic jump such as sequent depth ratio, length of jump ratio, length of the roller and energy dissipation ratio, consequently the dimensions of stilling basin changed. In this study hydraulic jump investigated on smooth bed (without any appurtenances) for three adverse slopes (- 0.03, - 0.045, - 0.06) in addition to horizontal bed slope, the experiments were applied for the range of Froude number (Fr1) between 3.99 and 7.48. The results showed a reduction about10 % in sequent depth ratio, 22.1 % in length of jump ratio, 20.51 % in length of roller ratio and 13.87% in the energy dissipation ratio when the adverse slope (- 0.06) used instead of horizontal bed for the same Froude numbers. Empirical equations for the sequent depth ratio, length of roller ratio and the energy dissipation ratio were obtained from the experimental data

Cyclic performance of cross restrained steel plate shear walls with transverse braces

This paper presents an investigation on the cyclic performance of cross restrained steel plate shear walls (SPSWs) with transverse braces. Transverse braces connecting to two columns are proposed to replace horizontal cross stiffeners on the infill steel plates. Effects of transverse braces on the performance of SPSWs are estimated through an experimental study and a finite element analysis. Two 1/3-scale two-story single-bay SPSW specimens, including one unstiffened SPSW and one cross restrained SPSW with transverse braces, are first tested under the quasi-static cyclic loading. Subsequently, finite element models for SPSWs are developed and verified by the test results. Cyclic performance of SPSW structures with different restrains for the infill steel plates are compared in terms of failure mode, loading capacity, energy dissipation capacity and stiffness degradation. Emphasis is given on the stress development and out-of-plane deformation of infill steel plates. The results show that use of transverse braces as the substitute of horizontal stiffeners enhances the loading capacity, energy dissipation capacity and ductility of SPSW structure. It is also effective to homogenize stress distribution and to restrain the out-of-plane deformation of infill steel plates, which finally decreases the additional bending moments applied to the columns. Compared with the unstiffened SPSWs, the maximum inward flexural deformation of columns in the cross restrained SPSWs with transverse braces is reduced by about 40.0%. It has demonstrated that the proposed cross restrainers combined with transverse braces are effective in improving the cyclic performance of SPSWs.

Experimental Studies on Cyclic Behavior of Corrugated Steel Plate Shear Walls

AbstractCorrugated steel plate shear wall (CoSPSW) is a lateral load–resisting system in which corrugated infill steel wall panels are embedded inside a steel boundary frame. Compared to flat steel...

Experimental Study on Low Cyclic Loading Tests of Steel Plate Shear Walls with Multilayer Slits

A new type of earthquake-resisting element that consists of a steel plate shear wall with slits is introduced. The infill steel plate is divided into a series of vertical flexural links with vertical links. The steel plate shear walls absorb energy by means of in-plane bending deformation of the flexural links and the energy dissipation capacity of the plastic hinges formed at both ends of the flexural links when under lateral loads. In this paper, finite element analysis and experimental studies at low cyclic loadings were conducted on specimens with steel plate shear walls with multilayer slits. The effects caused by varied slit pattern in terms of slit design parameters on lateral stiffness, ultimate bearing capacity and hysteretic behavior of the shear walls were analyzed. Results showed that the failure mode of steel plate shear walls with a single-layer slit was more likely to be out-of-plane buckling of the flexural links. As a result, the lateral stiffness and the ultimate bearing capacity were relatively lower when the precondition of the total height of the vertical slits remained the same. Differently, the failure mode of steel plate shear walls with multilayer slits was prone to global buckling of the infill steel plates; more obvious tensile fields provided evidence to the fact of higher lateral stiffness and excellent ultimate bearing capacity. It was also concluded that multilayer specimens exhibited better energy dissipation capacity compared with single-layer plate shear walls.

Experimental study on the hysteretic behavior of steel plate shear wall with unequal length slits

A steel plate shear wall with slits (SPSWS) is an effective anti-seismic component element, which owns good ductility and energy dissipation capacity. The infill steel plate is divided into flexural links by slits, which changes the path of conducting force. As a result, the SPSWSs obtain higher energy dissipation capacity and better ductility compared with conventional steel plate shear walls. However, both tests and finite element method (FEM) analysis have shown that the slits lower the ultimate bearing capacity and the lateral stiffness of the steel plate shear wall. In this case, two steel plate shear walls with unequal length slits (SPSWUS), i.e. papilionaceous SPSWUS and fusiform SPSWUS, are proposed and analyzed in this paper. Four 1/3-scaled test specimens are designed for the experimental study. Two of the specimens are SPSWUSs, and the other two are traditional SPSWSs. Testing of the systems were performed under cyclic lateral loading. Results show that SPSWUS has rather high energy dissipation capacity and good ductility as well as relatively high lateral stiffness and ultimate bearing capacity when compared with the traditional SPSWS. Experimental results correlate well with those from the finite element analysis, which validates the finite element model.

Performance of infill stiffened steel panel against blast loading

Abstract In blast loading, out-of-plane behavior of infill wall is activated initially. Contrary to other types of infill wall such as brick or concrete wall, infill steel plate wall exhibits more ductility. Since blast impulsive loading suddenly exerts a large amount of kinematic energy to infill wall, energy absorption characteristic of the infill wall should be taken into account, especially for protection of vulnerable buildings. Out-of-plane ductility of infill steel plate reduces the transmitted impulsive loading to the structure. In present study, out-of-plane behavior of infill steel panel has been studied as a sacrificial element. In-plane behavior of infill steel panel is also investigated as a lateral bearing system. In-plane action should satisfy both resistance and performance criteria. In this research, finite element analysis, including geometric and material nonlinearities is used for optimization of the steel plate thickness and stiffeners arrangement to obtain more efficient design for out-of-plane and in-plane actions. The results of analyses show that for out-of-plane action, the plate thickness and stiffeners arrangement can be determined such that on one hand, the impulse transmission can be minimized, and on the other hand, the maximum residual deformation can be limited to the predefined damage level. Additionally, the effect of stiffener arrangement on the performance of in-plane are studied and some practical rules have been derived for designing the infill steel panel against blast.