Steel-concrete Composite Shear Walls Research Articles

Experimental and numerical study on seismic behavior of special shaped steel truss and concrete composite shear wall

A steel truss-concrete composite (STCC) shear wall is fabricated by replacing the reinforcement of the shear wall by steel truss, which has high bearing capacity, good fire resistance, good seismic performance, and an easy construction. In order to investigate the seismic performance of special shaped composite shear wall, a quasi-static test was carried out on four T-shaped and two L-shaped composite shear walls. The results showed that the change of diagonal bracing form from strip steel to channel steel can improve the ductility and energy dissipation capacity of the shear wall and delay the strength degradation. Increasing the thickness of steel vertical supports can effectively improve the initial stiffness, while decreasing the thickness of diagonal braces will reduce the bearing capacity of the wall. The strength and stiffness of shear walls loaded along the web in the positive direction (flange in tension) is high, but the ductility is relatively poor when compared with walls loaded in the negative direction (flange in compression). Numerical models were established by ABAQUS, in which the steel hysteretic constitutive model was adjusted to simulate the influence of bond-slip effect. The influence of shear span ratio, axial load ratio, steel ratio of vertical support, volumetric ratio of diagonal brace, tilt angle of diagonal brace and horizontal force direction on the seismic performance of T & L shaped composite shear walls were analyzed. Finally, a design method was proposed, and the calculated results by the design method were in good agreement with the test.

Lateral load response of L-shaped steel–concrete composite shear walls using multi-partition steel tube

Behavior of L-shaped multi-partition steel–concrete composite shear walls (MP-SC-CSWs) subjected to the cyclic lateral load is experimentally and numerically evaluated. Such composite shear walls possess proper capacity, stiffness, and ductility, as the steel tube strengthened by inner steel plates considerably confines the infill concrete. Four large-scale L-shaped MP-SC-CSW specimens were designed, fabricated, and tested. The L-shaped specimens were exposed to lateral hysteretic loading and axial compression loading. The experimental parameters were axial load ratios and height-to-depth ratios (wall aspect ratios). The experimental results indicated that the L-shaped MP-SC-CSWs had high lateral capacities, energy dissipations, and good ductility. Based on the experimental observations, specimens failed in flexure mode. Increasing the axial load ratio enhances the capacity to dissipate energy but decreases the ductility. The tested specimens could meet the drift requirement of the specification even when subjected to a high design axial load ratio of 0.76. Additionally, the wall aspect ratios had little influence on the ductility. 3D nonlinear finite element models of tested specimens were established and verified with test results to conduct further numerical studies. A simplified method based on the plastic stress distribution was developed and confirmed by the experimental and finite element analysis to calculate the flexural capacities of MP-SC-CSWs.

Axial-flexural strength of steel-concrete composite shear walls

A predictive equation is proposed for the axial-flexural strength of rectangular and flanged Composite Plate Shear Walls-Concrete Filled (C-PSW/CF), with and without endplates and boundary elements. The proposed equation is based on plastic stress distribution, adjusted by coefficients to account for influential design parameters. The adjustment coefficients are established by a regression analysis performed on the data developed using an extensive numerical parametric study. The continuum-based finite element model used for the simulations is first validated using the available test data. The effects of various design variables, including the aspect ratio, slenderness ratio, reinforcement ratio, axial load ratio, infill concrete compressive strength, and yielding strength of the steel faceplates on axial-moment are then numerically examined. Four cross-sections, including double skin plate, double skin plate with endplates, double skin plate with boundary elements, and double skin plate with flanges, are considered. The results are used to develop a new predictive equation to obtain the flexural strength of C-PSW/CFs in presence of axial loading. The proposed equation is finally validated using the experimental test data and its accuracy is evaluated by comparing it to available predictive equations and the method proposed by the 2016 AISC Seismic Provisions. The results show that the proposed design equation can well predict the flexural moment capacity of C-PSW/CFs with various cross-sections in presence of axial loading.

Seismic behavior of composite shear walls with boundary columns using rectangular and U-shaped concrete-filled steel tubes

Steel-concrete composite shear walls with boundary concrete-filled steel tube (CFST) columns have drawn the attention of researchers due to their good seismic performance such as high strength, ductility and energy dissipation capacity. The reported study proposes a novel composite shear wall design that aims to complete the majority of the work in the factory, leaving only concrete pouring, steel welding, and formwork removal to be done on-site, so that the constructional time and cost can be saved. Two types of CFSTs were used for the boundary columns of composite shear walls, one is conventional rectangular CFSTs, another one is U-shaped CFSTs. In order to study the seismic behavior of the novel composite shear walls, cyclic loading tests were conducted on four full-scale specimens. The bearing capacity, energy dissipation, skeleton curves, hysteretic loops, deformation capacity and failure mode are analyzed. The experimental results have demonstrated that the bearing capacity and stiffness of shear walls with U-shaped CFST columns are slightly higher than that of shear walls with rectangular CFST columns, whereas the latter has better deformation capacity. In addition, the reported study investigated the methods of calculating the shear capacity of the novel composite shear walls and provided recommendations on the calculation method to be used for design and structural analysis.

Study on seismic behaviors of steel–concrete composite shear walls with novel corner designs

Steel–concrete composite shear walls are common structures that resist lateral forces and are typically damaged at the corners under seismic loading. In this study, novel corner designs of steel–concrete composite shear walls were proposed based on the design concept of plastic damage relocation. The seismic behavior of the designed corner structures of the steel–concrete composite shear wall was investigated using a low-cyclic lateral loading test. The failure mode, hysteretic curve, crack development, energy dissipation capacity, and stiffness degradation were analyzed based on the experimental results. To optimize the proposed corner designs, a finite element model was developed and validated experimentally, and a parametric study was conducted to determine the effects of the length–width ratio (α) and thickness ratio (β) of the stiffer to the steel plate and thickness ratio (λ) of the corner section steel to the steel plate on the seismic behaviors of the proposed composite shear wall. The experimental results showed that the seismic performance of the proposed steel–concrete composite shear wall was much better than that of a conventional shear wall. The results of the parametric study suggest that β and λ have little effect, and α should be 0.2 to achieve optimal seismic performance. This study provides a basic measurement to improve the seismic performance of steel–concrete composite shear walls, and promotes their development and application.

Investigation of the Influence of Design Parameters on the Strength of Steel–Concrete Composite Shear Walls by Finite Element Simulations

In this paper, the influence of design parameters on the strength of steel–concrete composite shear walls is investigated by means of finite element (FE) simulations. The shear wall typology studied in this paper consists of multiple composite plate shear wall-concrete encased on one or both sides of the plates. The FE models include contact technology to capture debonding between concrete and steel, tensile cracking in concrete, and large deflection theory involving local instabilities. Some design parameters considered in this work are the height-to-width ratio of the steel plates and their thickness, number of steel plates, the cross-section of the columns, and the height-to-width ratio of the shear wall. Furthermore, a sensitivity analysis of the normalised shear strength per unit cost of structure for these design parameters is also studied. Our numerical predictions are validated successfully with experimental data reported in the literature, revealing the predictive capabilities of the model. The present results provide further insight into the structural behavior of steel–concrete composite shear walls and pave the way for the future development of more efficient and innovative steel–concrete composite systems.

Eccentric behavior of l-shaped Multi-partition Steel-Concrete composite shear walls

An l-shaped composite shear wall, comprised of a multi-partition steel tube and concrete, is developed to improve the behavior of the l-shaped component. It possesses high load-resisting strength and good ductility as it makes better use of steel and concrete. Eleven samples were tested under eccentric load to determine the impacts of the depth, breadth, and load angle. The experimental results showed that the eccentric strength of the specimen under a load angle π was higher than that of the specimen under a load angle of 0. The specimens failed in out-of-plane and in-plane flexural modes when the depth-to-width ratios were different. Then, the finite element (FE) model using an improved constitutional relation of concrete was established to analyze the eccentric mechanism of the l-shaped composite shear walls. Furthermore, parametric analysis using the FE model was taken to determine the key factors of eccentric behavior. Compared to the design methods specified in EC4, AISC, and CECS, it was found that the calculated capacity for the stub was underestimated while the calculated capacity of the slender components was overestimated. The simplified formulas were presented for predicting the N-M curves based on the experimental and FE analysis and it could conservatively include the influence of the load angle and the relative slenderness.

Seismic behavior of steel truss and concrete composite shear wall with double X-shaped braces

Aiming to enhance the seismic performance and assembly of reinforced concrete (RC) shear walls, a novel steel truss and concrete composite (STCC) shear wall with twin X-shaped braces are proposed. Four STCC shear walls and one RC shear wall were tested under cyclic lateral and constant axial load to determine the effect of the number of channel columns and the addition of a crossbar on the seismic performance of STCC walls, as well as the difference in the seismic performance between the STCC wall and RC wall. Based on the test results, an optimal truss design is presented. Additionally, a comprehensive parametric analysis was carried out on 27 finite element models to investigate the influence of critical factors, such as the axial load ratio, the steel ratio of embedded steel columns, and the volumetric ratio of embedded braces, on the seismic performance of STCC walls. Results indicated that the ductility and the energy dissipation of the STCC shear walls were significantly improved, consequently reducing the number and extension of concrete cracks. Double channel columns could improve the bearing capacity of the STCC walls and provide sufficient support for X-shaped braces. Moreover, adding a crossbar could reduce the stiffness and bearing capacity degradation rate of the wall, but strengthening the connection between the column and the reinforcement inside the bottom foundation is recommended. The axial load ratio and the steel ratio of channel columns had more significant influence on the bearing capacity of STCC walls than the volumetric ratio of embedded braces. Finally, a calculation method is proposed, and the calculated results are in good agreement with the test findings.

Cyclic behavior of low shear-span ratio dovetailed profiled steel–concrete composite shear walls

Dovetailed profiled steel–concrete composite shear wall (DPSCW) is composed of two skins of dovetailed profiled steel sheeting (DPS) and concrete in between, which is a novel composite member with the potential to serve as a lateral resistant member in low and medium-rise building structures. In addition to functioning as shear connectors to enable the steel–concrete composite action, the dovetailed ribs of DPS embedded in the concrete also make the concrete panel between the DPSs partially slit in the thickness direction, leading to improved seismic performance. This study presents experimental and numerical analyses on the cyclic behaviour of low shear-span ratio DPSCW under combined axial and cyclic lateral loads. Accordingly, two DPSCW specimens with different thickness ratios (ratio of the thickness of the concrete not penetrated by the dovetailed slit to the wall thickness) were tested for failure. All specimens failed in a ductile manner and experienced a flexure-shear mixed mode. The lateral stiffness increased with an increase in the thickness ratio, and the deformability and energy dissipation capacity were reduced. Subsequently, numerical studies were performed to further investigate the failure mechanism of DPSCWs and the effect of the thickness ratio on its lateral behaviour. The dovetailed slits in the concrete panel enable the DPSCW to exhibit an obvious two-stage mechanical response, and a reasonable thickness ratio between 0.19 and 0.5 is recommended. Moreover, simplified models were established to evaluate the lateral resistance of low shear-span ratio DPSCWs. The estimation formulae were found to coincide with the experimental and numerical simulation results.

Modelling of Cyclic Load Behaviour of Smart Composite Steel-Concrete Shear Wall Using Finite Element Analysis

In recent years, steel-concrete composite shear walls have been widely used in enormous high-rise buildings. Due to their high strength and ductility, enhanced stiffness, stable cycle characteristics and large energy absorption, such walls can be adopted in auxiliary buildings, surrounding the reactor containment structure of nuclear power plants to resist lateral forces induced by heavy winds and severe earthquakes. The current study aims to investigate the seismic behaviour of composite shear walls and evaluate their performance in comparison with traditional reinforced concrete (RC) walls when subjected to cyclic loading. A three-dimensional finite element model is developed using ANSYS by emphasising constitutive material modelling and element type to represent the real physical behaviour of complex shear wall structures. The analysis escalates with parametric variation in reinforcement ratio, compressive strength of the concrete wall, layout of shear stud and yield stress of infill steel plate. The modelling details of structural components, contact conditions between steel and concrete, associated boundary conditions and constitutive relationships for the cyclic loading are explained. The findings of this study showed that an up to 3.5% increase in the reinforcement ratio enhanced the ductility and energy absorption with a ratio of 37% and 38%, respectively. Moreover, increasing the concrete strength up to 55 MPa enhanced the ductility and energy absorption with ratios of 51% and 38%, respectively. Thus, this improves the contribution of concrete strength, while increasing the yield stress of steel plate (to 380 MPa) enhanced the ductility (by a ratio of 66%) compared with the reference model. The present numerical research shows that the compressive strength of the concrete wall, reinforcement ratio, layout of shear stud and yield stress of infill steel plate significantly affect ductility and energy absorption. Moreover, this offers a possibility for improving the shear wall’s capacity, which is more important.

An investigation of the effects of aspect ratio and opening on CSPSW and TSCSW

PurposeThis paper aims to study, the effects of opening shape, size and position as well as the aspect (height-to-length) ratio on the shear capacity, stiffness, ductility and energy dissipation capacity of triple-skin profiled steel-concrete composite shear wall (TSCSW) and investigate and compare them to those of concrete-stiffened steel plate shear walls (CSPSW). Two kinds of opening, circular and square, with different sizes and positions and two aspect ratios of 1:1 and 3:1 are considered in the simulations.Design/methodology/approachThis study presents a novel TSCSW and compares its behavior with the existing CSPSW under the effect of monotonic and cyclic loadings. TSCSW is composed of three corrugated steel plates filled with concrete. The two external side plates are connected to the concrete core by means of several intermediate fasteners and the third one is an inner steel plate embedded within the concrete panel. The internal plate is a buckling restrained plate surrounded by concrete. This is the main superiority of TSCSW over other kinds of existing composite shear walls.FindingsThe results show that the shear capacity and the energy dissipation capacity of the proposed composite wall, TSCSW, are respectively about 16 and 12% higher than those of CSPSW when there is no opening. If an opening is considered in the wall, as the size of the opening is increased, the shear capacity, stiffness, ductility and absorbed energy of the two walls are decreased similarly. The destructive effect of square openings on the performance of the walls is more than that of circular openings.Originality/valueThis is an original work.

Axial and hysteretic behavior of T-shaped steel–concrete composite shear walls

Multi-partition steel tube formed T-shaped composite shear wall is a new type of composite wall which enhances the structural performance compared to a traditional composite shear wall. To clearly understand the behavior of such shear walls, eight half-scaled specimens were tested to study their axial and seismic behavior. The failure mechanism, structural behavior and energy dissipation ability were observed according to the experiments. The axial experiments showed that the strength of such cross-section was higher than the sum of capacities of concrete and steel tube as the multi-partition steel tube could confine the concrete well. Meanwhile, the ductility of specimens was good. For seismic experiments, the specimens exhibited high strength, good ductility and excellent energy dissipation ability. When the axial load ratio increased, the lateral load resistance capacity and energy dissipation capacity increased obviously. Although the axial load ratio was beyond the limitation of the current Chinese standard, the drift angle could still satisfy the requirement of the standard. The experimental results were used to compare with those calculated results according to some codes including EC4, CECS and AISC.

Seismic behaviors of steel truss-embedded steel-concrete composite shear walls

This study firstly proposed a novel type of steel truss-embedded steel-concrete composite shear wall (STSCW) for super-tall buildings. The embedded steel truss in this shear wall provides lateral resistance even after concrete crushing, delays concrete failure, and serves as an effective connection to the external truss beam in mega-frame structures. Four cyclic loading tests were conducted on the proposed STSCWs to investigate their seismic behaviors. In this experimental program, the investigated parameters included the axial force ratio and the steel-concrete interface with/without studs. The results of the cyclic loading tests demonstrated that all the STSCWs failed in flexure, and exhibited the characteristics of local buckling of faceplates, vertical fracture of the welds at corners, tensile fracture of the steel side plates, concrete crushing, chord necking, or buckling of the embedded steel truss. The axial force ratio was found to significantly affect the energy dissipation and deformation capacities of the STSCWs. In addition, the deformation of embedded steel truss worked well with the steel-concrete-steel sandwich wall (SCSSW) before the yielding point. Welding the studs on the flange surface of the embedded steel truss improved the deformation compatibility between the embedded steel truss and SCSSW wall. Moreover, the embedded steel truss failed in flexure via chord member buckling or necking.

BEHAVIOR OF STEEL PLATE-CONCRETE COMPOSITE SHEAR WALL UNDER CYCLIC LOADING

Steel-Concrete composite shear wall has become popular recently as it compensates for the disadvantages of concrete and steel plate shear walls and combine the advantage of both. However, there is no detail study that identifies the most critical parameters. This study aims at investigation of steel plate-concrete composite shear wall behavior under cyclic loading with variables such as concrete strength, grade of steel plate, total number of tie constraints and thickness of steel plate. ABAQUS/Standard is used for numerical modeling in this study. As the concrete strength decreases from 86.1Mpa to 45Mpa, the load capacity declined by 11.76% and higher stiffness was recorded in specimen with higher grade of concrete. The ductility factor is inversely proportional to grade of concrete from 86.1Mpa to 60Mpa which increases from 4.26 to 4.68 and the ductility factor of specimen with 45Mpa strength is recorded as 3.81. The energy dissipation capacity is directly proportional to the grade of concrete used. Using high grade steel plate increases the lateral load capacity significantly and exhibited more ductile behavior. Specimen with S355 steel grade exhibited 14.01% increment of the average load capacity while the specimen with S245 steel grade has shown reduction by 9.21%. Similarly, the ductility factor and energy dissipation capacity of specimen with variable grade of steel are directly proportional. Reduction of tie constraints has no significant effect on the behavior in this study due to high confinement effect of concrete by surrounding steel plate. Specimens with thicker steel plate exhibited good energy dissipation capacity.

A fibre-based modelling technique for the seismic analysis of steel–concrete composite shear walls

Steel–concrete composite shear wall offers a favourable lateral strength and deformation ductility for seismic applications while significantly shortening the project schedule through eliminating the use of formworks and taking advantage of modular construction methodology. This paper presents a fibre-based modelling technique for simulation of the cyclic nonlinear response of composite walls by taking advantage of existing reinforced concrete and steel plate shear wall models. The improved modelling technique for cyclic analysis of composite walls that benefits from the macro models available for steel and concrete shear walls is introduced. The model is validated using experimental test data from 20 wall specimens. A sensitivity analysis is performed to examine the influence of various geometrical and material properties using the proposed modelling technique. A step-by-step modelling recommendation is finally proposed. The results show that the proposed modelling technique can efficiently be used to reproduce the nonlinear cyclic response of composite walls.

Behavior of Curved Double Steel-Concrete Composite Shear Walls Under Cyclic Loading

In this study, effects of different curved structures on mechanical behavior of curved double steel-concrete composite shear (SC) walls under cyclic loading were investigated numerically. Firstly, the experimental results of a straight SC wall under cyclic loading were used to validate numerical result. After then, curved SC walls were designed in ABAQUS according to different radius-thickness (R/t) ratios (5,10,15,20,25,30,40). In numerical studies, in-plane monotonic response, cycling response, and out-of-plane monotonic response were investigated by changing the loading. The results showed that among all parameters, the R/t ratio:5 has better seismic performance by 11.87% than straight SC wall under cyclic loading. In addition, it was found that when the ratio of the radius of curvature to the section thickness values were greater than 10, curved SC walls behaved as straight SC walls. When the R/t ratio was bigger than 10, the ultimate load and damage of wall load dropped consistently. According to in-plane monotonic response results, R/t ratio:5 has a 13.6% better peak force than straight wall when it is compared with other R/t ratio values. Calculated results showed that although there is no effect in bearing capacity when R/t ≥ 10, it increased by 35.4% when R/t is 5.

MECHANICAL BEHAVIOR RESEARCH OF A NEW TYPE OF DOUBLE-SKIN STEEL-CONCRETE COMPOSITE SHEAR WALL

A new type of double-skin steel-concrete composite shear wall with vertical seams between shear wall and boundary elements were proposed, and the wall plates are connected using bolts and plate connectors. Quasi-static tests on four specimens were carried out to study the seismic behavior of the composite shear wall. The results of tests were compared with the same types of composite shear walls without vertical seams, in which the upper and lower steel faceplates were weld together. The test results showed that the new type of double-skin steel-concrete shear wall had good seismic performance. The average values of the yield drift angle and ultimate drift angle of the four specimens were 1/169 and 1/37, respectively. The seams weakened the bearing capacity of the test specimen, but improved the ductility and the performance of energy consumption. The failure mode of specimens was bending failure at the bottom of the wall, indicating that the stress between walls could be effectively transmitted through bolts and plate connectors. A finite element model was developed using ABAQUS to analyze the performance of this type of double-skin composite shear wall. The force mechanism of bolt group in the plate connectors, the effects of vertical seams on the failure mode of boundary columns, and other factors including strength of material, shear-span ratio and axial compression ratio which may affect the performance of the composite shear wall, were also analyzed based on the FEM model.

Axial and Bending Bearing Capacity of Double-Steel-Concrete Composite Shear Walls

Double steel-concrete composite shear wall is a novel composite structure. Due to its good mechanical properties, it has been considered as a substitute for reinforced concrete walls in nuclear facilities, marine environmental structures, and high-rise buildings. However, the design method of the double-steel concrete composite shear wall is lacking. The purpose of this paper is to propose the bending capacity formula under large and small eccentric loads. By summarizing the test results of 49 steel-concrete composite double shear walls under cyclic loading from different studies, it was found that the bending failure of double-steel-concrete composite shear walls was featured by the concrete crushing at the bottom. A finite element model was established and it could simulate the axial and bending performance of double steel-concrete composite shear walls reasonably well. According to the experimental results and FE analysis, the primary assumptions for calculating the axial and bending bearing capacity of the double steel-concrete composite shear walls were proposed. Based on these assumptions, the bearing capacity formulas were derived according to the equilibrium theory of the cross section. The calculation results obtained by the bearing capacity formulas were in good agreement with the test results.

Bearing capacity of composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall

Composite shear walls are widely used in high-rise buildings because of their high bearing capacity. To improve the bearing capacity of ordinary shear walls, restraining elements are usually installed at both boundaries or within the wall body. In this article, two different restraining elements, namely, a rectangular steel tube and a column-type reinforcement (the whole wall body was restrained by segmented stirrups and tied by diagonal bars), were applied to the boundary frame and wall body of the shear wall either jointly or separately. A new type of steel-concrete composite shear wall, referred to as a composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall, was proposed. In addition, three specimens with different restraining elements, namely, a column-type reinforced shear wall, a concrete-filled steel tube boundary shear wall and an ordinary reinforced concrete shear wall, were presented for comparison. The influences of the two different restraining elements on the seismic performance and bearing capacity of the shear walls were analyzed from four perspectives of failure mode, hysteresis behavior, stiffness and residual deformation, and the equivalent lateral pressures of the two restraining elements were calculated. Based on the plane-section assumption, expressions for the crack, yield, peak and ultimate bearing capacities were derived, and the effects of the two restraining elements on the peak and ultimate bearing capacities were considered. The results show that these two restraining elements significantly improved the bearing capacity of the shear wall specimens, and the concrete-filled steel tube restraining element was more effective than the column-type reinforced restraining element. Finally, the calculated values of the bearing capacity of the four different restraining elements of the shear wall specimens proposed in this article were in good agreement with the experimental values.

Macro modeling of steel-concrete composite shear walls

To date, many researchers have developed various types of macro models to simulate the general response of conventional steel plate and reinforced concrete shear walls. Although extensive numerical and experimental studies have been conducted to assess the seismic response of steel-plate concrete composite shear walls, a robust macro-model for simulation of the cyclic response of such systems has not been developed yet.Herein, a fiber-based model is proposed to simulate the nonlinear seismic response of SC walls using PERFORM-3D program. The details of the proposed model, including material properties, element type, and boundary condition, are presented. The proposed model is validated using the available test data of seventeen SC wall specimens with and without boundary elements. Based on the analysis results, this novel approach can capture the global response of SC shear walls including initial stiffness, peak shear strength and its corresponding displacement, stiffness and strength degradation, and pinching behavior accurately. The proposed macro model for SC shear walls can be considered as a reliable tool to extend the engineering application of SC walls in the building industry.