Composite Steel-concrete Shear Walls Research Articles

Finite element analysis on composite steel-concrete shear walls with centered and staggered openings

Present paper presents a comparative study made on the seismic performance of composite steel-concrete shear walls with rectangular openings, by performing numerical analyses using ATENA 3D software. Two specimens were designed at a reduced scale 1:3 having similar arrangements in the cross-section and the same geometry. First element was conceived with centered openings while the second one was designed with staggered openings. Steel connectors disposed as horizontal stiffeners were used to design and to assure the full connection between the structural steel profiles embedded in the edges and the concrete core. The openings that were considered on each story of the walls, were having the dimension of a common architectural door. A part of the results recorded from the experimental tests were used to calibrate the numerical models. This study aims to establish the seismic performance and to investigate the influence of the openings and the geometric position on the overall seismic behavior of the composite shear walls. Key parameters which describe the seismic performance of structural elements such: bearing capacity, deformation capacity, stiffness degradation, cracks and strain development are compared between the specimens and discussed. The results showed that different arrangements of the openings could significantly modify or increase the seismic performance of the composite structural walls.

Effect of Type and Distribution of Shear Studs on the Behavior of Composite Steel-Concrete Shear Walls

In this research the in-plane shear behavior of composite steel-concrete shear walls was investigated by taking into account the following variables: steel plate thickness, the spacing between shear studs, the shape and type of the shear studs and consideration of the minimum reinforcement in the wall section. Several finite element models were analyzed and numerical results of two models were verified with available experimental results in the literature. Results revealed that increasing the thickness of the steel plate increases the yield and ultimate shear strengths; moreover, increasing the spacing between shear studs reduces the shear resistance to some extent; furthermore, steel-plate composite (SC) walls with iron angles have higher yield and ultimate shear resistance than walls with studs; finally, the wall with the minimum reinforcement behaved better than the wall with no reinforcement in terms of ductility and shear strength.

Seismic Behaviour of Composite Steel Fibre Reinforced Concrete Shear Walls

In this paper is presented an experimental study conducted at the “Politehnica” University of Timisoara, Romania. This study provides results from a comprehensive experimental investigation on the behaviour of composite steel fibre reinforced concrete shear walls (CSFRCW) with partially or totally encased profiles. Two experimental composite steel fibre reinforced concrete walls (CSFRCW) and, as a reference specimen, a typical reinforced concrete shear wall (RCW), (without structural reinforcement), were fabricated and tested under constant vertical load and quasi-static reversed cyclic lateral loads, in displacement control. The tests were performed until failure. The tested specimens were designed as 1:3 scale steel-concrete composite elements, representing a three storeys and one bay element from the base of a lateral resisting system made by shear walls. Configuration/arrangement of steel profiles in cross section were varied within the specimens. The main objective of this research consisted in identifying innovative solutions for composite steel-concrete shear walls with enhanced performance, as steel fibre reinforced concrete which was used in order to replace traditional reinforced concrete. A first conclusion was that replacing traditional reinforcement with steel fibre changes the failure mode of the elements, as from a flexural mode, in case of element RCW, to a shear failure mode for CSFRCW. The maximum lateral force had almost similar values but test results indicated an improvement in cracking response, and a decrease in ductility. The addition of steel fibres in the concrete mixture can lead to an increase of the initial cracking force, and can change the sudden opening of a crack in a more stable process.

08.39: Experimental investigations on performance enhancement of composite steel concrete shear walls by using steel fibre reinforced concrete

ABSTRACTThe paper presents further results of an experimental program that was conducted at the Politehnica University Timisoara, studying the behaviour of Composite Steel‐Fibre‐Reinforced‐Concrete shear Walls (CSFRCW) with partially encased profiles. Use of such shear walls represents a widespread solution for providing a lateral load resisting structural system, especially in the case of medium and high‐rise buildings placed in seismic areas. As previous theoretical and experimental studies have proved the performance of such system, the foremost objective of the experimental program consisted in identifying innovative solutions for composite steel‐concrete shear walls with enhanced performance, as steel fibre reinforced concrete which was used in order to replace traditional reinforced concrete. The program consisted in tests on 6 specimens designed as 1:3 scale steel‐concrete composite elements, leading to an experimental matrix that enabled complex comparisons of various solutions. Thus, a steel reinforced concrete shear wall (without any encased profiles) was used as reference, configuration/arrangement of steel profiles and ratios of steel fibre reinforcement were varied within the other five specimens. The effective stiffness, strength and ductility is evaluated using the experimental results.

Numerical study on important parameters of composite steel-concrete shear walls

In recent years, steel-concrete composite shear walls have been widely used in enormous high-rise buildings. This paper demonstrates nonlinear numerical studies on composite steel-concrete shear walls affecting cyclic loading. Five types of three-dimensional finite element model is developed using ABAQUS emphasizing constitutive material modeling and element type to represent the real physical behavior of complex shear wall structures. Modeling details of structural components, contact conditions between steel and concrete, associated boundary conditions, and constitutive relationships for the cyclic loading are explained. Load versus displacement curves, peak load, and hysteretic characteristics are verified with experimental data. Present study investigates important parameters such as concrete failure, hysteresis response, out of plan displacement, frame drift, and dissipated energy. The findings revealed that steel frame with concrete, on one side of shear plate, had better dissipation energy function compared with other types. Comparing the results, it was clearly observed that the lateral stiffness of the system isn't affected by changing the distance between connectors and concrete cover thicknesses. Numerical results show that shear steel plate buckling was reduced by increasing concrete thickness, and energy dissipation increased by reducing connectors' distance.

MODELING OF NONLINEAR CYCLIC LOAD BEHAVIOR OF I-SHAPED COMPOSITE STEEL-CONCRETE SHEAR WALLS OF NUCLEAR POWER PLANTS

In recent years steel-concrete composite shear walls have been widely used in enormous high-rise buildings. Due to high strength and ductility, enhanced stiffness, stable cycle characteristics and large energy absorption, such walls can be adopted in the auxiliary building; surrounding the reactor containment structure of nuclear power plants to resist lateral forces induced by heavy winds and severe earthquakes. This paper demonstrates a set of nonlinear numerical studies on I-shaped composite steel-concrete shear walls of the nuclear power plants subjected to reverse cyclic loading. A three-dimensional finite element model is developed using ABAQUS by emphasizing on constitutive material modeling and element type to represent the real physical behavior of complex shear wall structures. The analysis escalates with parametric variation in steel thickness sandwiching the stipulated amount of concrete panels. Modeling details of structural components, contact conditions between steel and concrete, associated boundary conditions and constitutive relationships for the cyclic loading are explained. Later, the load versus displacement curves, peak load and ultimate strength values, hysteretic characteristics and deflection profiles are verified with experimental data. The convergence of the numerical outcomes has been discussed to conclude the remarks.

Theoretical and experimental study on composite steel–concrete shear walls with vertical steel encased profiles

The present work describes the theoretical study and the experimental tests on composite steel–concrete shear walls with steel encased profiles (CSRCW), performed at Politehnica University of Timişoara, Romania. The composite steel–concrete structural shear walls with steel encased profiles can be used as horizontal resisting systems for buildings that require considerable large horizontal load capacity. The study consists in numerical analysis and tests on 1:3 scale experimental steel–concrete composite elements. The experimental elements differ by the arrangement of the steel shapes embedded in the cross section of the wall and by the cross section type of the steel encased element. Headed steel studs are provided to ensure the connection between the steel profiles and the concrete. The aim of this study is to analyze the nonlinear behavior of elements, focused on the connection between the steel profiles and the concrete respectively, to compare the behavior of shear walls with different steel shape encased profiles with typical reinforced concrete shear walls. Using the tests performed until failure, the maximum load, the deformation capacity and the dissipated energy were evaluated.