Performance Of Composite Shear Walls Research Articles

Macro modeling of composite shear wall with stiffened steel plates and infilled concrete

In high-rise buildings, traditional concrete shear walls have many limitations. This paper proposes a composite shear wall with stiffened steel plates and infilled concrete (CWSC), offering high bearing capacity, significant deformation capacity, and energy dissipation ability. The ductility coefficient ranges from 2.75 to 3.56, with an average ultimate drift ratio of 1/30, surpassing the 1/80 limit specified in the shear wall code. This paper also presents a macro model for CWSC based on experimental results. Studying the strain gauges in the steel plate reveals the stress mechanism in the composite shear wall, where the central region experiences shear forces while the corner regions undergo tension and compression. A comparison between the results of the macro model and existing experimental data demonstrates the ability of the model to accurately predict the hysteresis curve and seismic performance of CWSC. Likewise, a comparison of the macro model with hysteresis and skeleton curves from 15 different literature sources on composite shear walls shows that the macro model can effectively simulate the seismic performance of composite shear walls reported in previous studies. This confirms the applicability of the macro model.

Performance of composite shear walls strengthened with FRP and subjected to blast load

The present paper aims to explore the performance of composite shear walls reinforced with Fiber Reinforced Polymer (FRP) sheets, subjected to blast loads. The finite-element method (FEM) implemented in the ABAQUS software is used to evaluate several numerical models to meet this objective. The parametric behavior of the system under the effect of blast load intensity was investigated, along with the FRP sheet material, concrete compressive strength, and also the geometric characteristics of wall components such as its thickness, spacing of FRP sheets, and thickness of the cross-sectional shape of the steel plates under the effect of blast load. It was found that the reinforcement of the composite shear wall by incorporating FRP sheets not only increases the stress absorption in the wall but also increases the load transfer capacity and leads to high energy dissipation using the polymer fibers. It has been found that carbon polymer sheets (CFRP) and glass polymer sheets (GFRP) have, respectively, the best and the weakest performance in shear wall stress absorption compared to AFRP sheets, and this is due to the tensile strength and low density of CFRP sheets. As the thickness of FRP sheets increases, the stress, strain and displacement created in the composite shear wall decrease, owing to the increase of the final strength, which is, in turn, the result of the increase in fiber thickness.

Seismic Performance of Composite Shear Walls Filled with Demolished Concrete Lumps and Self-Compacting Concrete after Fire

In order to provide a good solution for the treatment and utilization of construction waste, especially waste concrete and to promote the development of green construction to some extent, in this paper, a new composite shear wall filled with demolished concrete lumps (DCLs) and self-compacting concrete (SCC) was proposed, and its seismic performance after fire was investigated. Based on quasi-static tests of four composite shear walls filled with DCLs and SCC, three after a standard fire and one contrastive specimen without fire, the effects of fire exposure time, fire-retardant coating on the edge constraint steel pipe column, and the width-thickness ratio on seismic performance of composite shear walls after fire were studied. The failure patterns, bearing capacity, hysteretic loops, ductility, skeleton curves, rigidity degradation curves, and energy dissipation of shear walls were analyzed and compared. Test results indicate that the bearing capacity of the shear wall after 60 min of standard fire is slightly lower than the contrastive specimen without fire, but specimens still have good seismic performance. The interlayer displacement angle of the shear wall after a fire still meets the requirement of regulations. The fire-retardant coating on the edge of concealed steel pipe column has a limited effect on the seismic performance of specimens after a fire. The horizontal bearing capacity and energy dissipation capacity of shear walls after a fire can obviously be improved by properly increasing the width-thickness ratio.

Numerical study on the response of composite shear walls with steel sheets under cyclic loading

As an alternative to conventional reinforced concrete walls, composite shear walls have been studied recently due to their great advantages in terms of structural performance under seismic loading. Researchers usually use ready-made profiles for composite shear walls, but in this study L-shaped cold-formed steel sheets were selected for numerical analysis under lateral cyclic forces. A macroscale numerical model was developed using a fiber beam-column element with a shear spring model to reproduce the actual behavior of composite shear walls. In addition, the OpenSees-based model was verified against three experimentally tested composite shear walls and showed robust simulation ability. Moreover, in order to fully explain their effect on the performance of composite shear walls, the properties of L-shaped steel sheets were studied parametrically with the help of the numerical model in terms of thickness and yield strength. It was clear that increases in the sheets’ yield strength and thickness increased the lateral load-displacement capacity of the walls. It was thought that the two factors were connected in terms of their effects, and the L-shaped steel sheet arrangement in the boundary zone had essential participation in the total response of the composite shear wall under the applied loads.

Study of the Seismic Performance of Composite Shear Walls with Embedded Steel Truss For Use in High-rise Buildings

Abstract The composite wall with encased steel braces (ESB wall) is a novel type of steel–concrete composite wall that consists of a steel braced frame embedded in reinforced concrete. This arrangement is supposed to enhance the seismic performance of the wall, as the steel columns encased in the boundary elements can increase the flexural strength of the wall and the steel braces encased in the web can increase the shear strength. ESB walls have seen use in super tall building structures constructed in regions of high seismicity. The ESB walls are commonly used on stories where the shear force demand is very high. Currently, no design guidelines exist for the design of ESB Walls in the Eurocode. More research is required before a distinct set of guidelines can be prescribed for the design of ESB Walls. The present research will investigate behavior of composite walls with encased steel braces (ESB walls). Time history analysis will be performed to examine the shear strength and stiffness of the ESB walls. In this study, two frames with three floors and five floors will be modeled in ABAQUS software. Then the X- shaped braces and inverted V brace is added to frames. Later, reinforced concrete shear wall will be added to braced frames, so the steel braces encased in the reinforced concrete shear wall. Time history analysis, on the braced frames will be done Compare and note with each other. The results of the study are in good agreement with those of previous studies. However, none of these studies examined the effect of using V- and X-shaped struts and shear walls simultaneously, nor did they examine which struts reinforce the structures more strongly against earthquake vibrations. This has led the study to examine the effect of these reinforcements under various earthquakes. In future studies, reinforced concrete structures can also be used in addition to steel structures, and the results can be compared. In addition, these braces can also be used in other parts of the building. To meet this objective, one can use the very important data provided in this thesis, and ultimately better and more accurate results can be extracted using this approach. The main aim of this thesis is to study the effect of increasing the number of floors on how to extend the stress on the building structure. To this end, the number of floors increased from three to five. Therefore, it can be concluded that an increase in the number of floors also more than 5 storey causes stress values, but these modes are quite consistent with the three- and five-storey buildings.

Seismic performance of composite shear walls with embedded FCCCs in boundary elements

A novel composite concrete shear wall with FRP-Confined Concrete Cores (FCCCs) arranged in the boundary elements is proposed. A series of quasi-static tests are performed to evaluate the seismic performance of the proposed composite shear walls. The specimens are subjected to combined constant vertical loading and cyclic lateral loading. The tested variables include the concrete strength of FCCC, the number of FCCC in the boundary elements, and the cross-section of the composite shear wall. Based on the test results, systematic discussions on the seismic behavior of the composite shear walls, including the failure mode, the hysteretic response, the energy dissipation, the stiffness/strength degradation, etc., are presented. It is found that the composite shear walls demonstrate similar lateral load resistance but much better deformability and energy dissipation compared with ordinary RC shear wall. Finally, numerical simulations were performed based on the software OpenSees. The FE results were in good agreement with test results. The influence of various parameters on the seismic behavior of composite shear wall was discussed based on parametric studies.

Cyclic performance of composite shear walls with boundary elements

In the past three decades, several experiments were conducted to investigate the seismic behavior of composite plate shear walls (C-PSW) because of their advantages to conventional reinforced concrete (RC) and steel plate shear walls (SPSW). Numerical studies, however, are limited due to the complexities for the finite element modeling of the steel and concrete material behaviors and their composite action.Herein, the cyclic behavior of various C-PSW with and without boundary elements (BE) is investigated numerically. The effects of design parameters such as aspect ratio, axial load ratio, and the length of the BE on the response of C-PSW are investigated. The advanced finite element software LS-DYNA is utilized to develop the cyclic model of C-PSW. The LS-DYNA model is validated using the available experimental data in the literature. Numerical analyses indicate that the‌‌ BE has a significant impact on the stiffness, strength, and energy absorption of C-PSW especially in high aspect ratio walls. A simplified method is proposed to estimate the peak shear strength of C-PSW with BE using the results of the numerical and experimental study.

Seismic performance of composite walls with concrete-filled square steel-tube boundary element

This paper studies the seismic performance of composite shear walls with concrete-filled square steel-tube boundary element and innovative shear connections. Eight specimens were investigated by reversed cyclic load tests. The test parameters were the type of the shear connections, the arrangement of a steel beam in the middle of wall body, the concrete strength and the axial compressive load ratio. The failure mode, hysteretic behaviour, ductility, stiffness and strength degradation, energy dissipation capacity and strains development were studied. The test results show that the hysteresis curves of the composite shear walls were plumper compared with traditional concrete shear walls. Composite shear walls with concrete-filled square steel-tube boundary element have good seismic performance. The strong shear connections had a considerable effect on the seismic performance of this composite shear walls. There was no considerable difference in the effect on seismic performance for the arrangement of a steel beam in the middle of wall body. Finally, the restoring force model for composite walls with concrete-filled square steel-tube boundary element was developed with adequate accuracy.

Structural Performance of Composite Shear Walls under Compression

In order to research the effect of different layout forms of steel plate on the axial compression behavior of a steel plate-concrete composite shear wall, this paper presents the experimental results and analysis of the axial compression behavior of a composite shear wall, with different layout forms of steel plate. A total of three tests were carried out, composed of two composite walls with built-in steel plate, and one composite wall with two skins of steel plate. The gross dimensions of the three specimens were 1206 mm × 2006 mm × 300 mm. Experimental results show that the composite wall with two skins of steel plate has an optimal ability of elastic-plastic deformation, and the maximum axial compressive bearing capacity among the three specimens. Using the energy method, the critical local buckling stresses of steel plate were calculated, and compared with the yield stresses. According to different confined actions of concrete, concrete constitutive models were proposed, and the axial compressive strengths of confined concrete were calculated. Considering the local buckling of steel plate and confined concrete, the calculation formula of the axial compression of the composite wall was put forward, and the calculated results were in good agreement with the test results. Therefore, the different layout forms of steel plate have a great influence on its buckling, and on the concrete inhibition effect, which can affect the axial compressive bearing capacity of the composite wall.

Seismic Performance of Composite Shear Walls Constructed Using Recycled Aggregate Concrete and Different Expandable Polystyrene Configurations.

The seismic performance of recycled aggregate concrete (RAC) composite shear walls with different expandable polystyrene (EPS) configurations was investigated. Six concrete shear walls were designed and tested under cyclic loading to evaluate the effect of fine RAC in designing earthquake-resistant structures. Three of the six specimens were used to construct mid-rise walls with a shear-span ratio of 1.5, and the other three specimens were used to construct low-rise walls with a shear-span ratio of 0.8. The mid-rise and low-rise shear walls consisted of an ordinary recycled concrete shear wall, a composite wall with fine aggregate concrete (FAC) protective layer (EPS modules as the external insulation layer), and a composite wall with sandwiched EPS modules as the insulation layer. Several parameters obtained from the experimental results were compared and analyzed, including the load-bearing capacity, stiffness, ductility, energy dissipation, and failure characteristics of the specimens. The calculation formula of load-bearing capacity was obtained by considering the effect of FAC on composite shear walls as the protective layer. The damage process of the specimen was simulated using the ABAQUS Software, and the results agreed quite well with those obtained from the experiments. The results show that the seismic resistance behavior of the EPS module composite for shear walls performed better than ordinary recycled concrete for shear walls. Shear walls with sandwiched EPS modules had a better seismic performance than those with EPS modules lying outside. Although the FAC protective layer slightly improved the seismic performance of the structure, it undoubtedly slowed down the speed of crack formation and the stiffness degradation of the walls.