Shear Wall System Research Articles

Nonlinear Seismic Analysis of Perforated cold-formed steel shear wall with Upright Section

During the last few decades, cold-formed steel (CFS) is extensively used in mid- and low-rise housing due to the increasing demand of rapid constructions along with its various advantages in comparison with other structural material. Cold-formed steel framed shear walls (CFSFSW) are most common and primary lateral load resisting system. However, adopting it in the seismic zone is difficult, especially because many design components remain open. In this research an effort has been made to design the shear wall system with both unperforated and perforated upright sections using nonlinear static analysis method. In ABAQUS, a general-purpose finite element analysis software, three-dimensional models using shell elements are used to simulate a shear wall system. A comparative study regarding the lateral load capacities with respect to maximum allowable lateral deflection including different parameters like column sections, thickness and perforation arrangements are presented here. It was found that increasing thickness and including Chanel stiffeners improves the lateral strength of original upright section. The developed modelling protocol helps to estimate its lateral performance under earthquake with reasonable accuracy.

Experimental and numerical studies of fire behavior of cold-formed steel center-sheathed walls subjected to gravity loading

It is a challenge for the conventional cold-formed steel (CFS) sheathed wall system to be adopted in multi-story buildings due to its limited lateral load capacity and stiffness. Therefore, an innovative cold-formed steel center-sheathed shear wall (CFSCSSW) system with better lateral load capacity and stiffness has been proposed and shown its potential application in multi-story buildings. However, the fire performance of CFSCSSW has become one of the major issues which have yet to be investigated and thus become the focus of the present paper, underpinned by tests and numerical simulations. In this study, a full-scale test at room temperature was firstly conducted on a CFSCSSW to obtain its vertical load capacity, while another four full-scale fire tests were then carried out with applied gravity loads to investigate the influence of the interior stud, load ratio, and aspect ratio on fire behavior of the walls. Following the tests, 11 finite element models were subsequently developed to investigate the influence of various critical parameters, such as the axial load ratio, aspect ratio, and end stud thickness, on the fire resistance of CFSCSSW. The fire test results showed that the heat loss of the wall surface could be more than 40% during the temperature transition from the fire exposed side to the cold side. It is found that the presence of interior stud, increasing the aspect ratio beyond 3.0 as well as the load ratio to be greater than 0.3 can result in a transition of the failure mode of the wall from global buckling to local buckling. The critical temperature declines approximately 12% if the load ratio increases by 0.1. The fire resistance of the wall was slightly improved with the increase of the aspect ratio. The end stud thickness of 2 mm is recommended preferentially based on the parametric results. In addition, it was found that the presence of the interior stud has little influence on the fire resistance of the walls.

Calculations of additional axial force and coupling ratio for coupled shear walls

The additional axial forces (AAFs) in walls and coupling ratio (CR) of coupled shear wall (CSW) systems have significant effects on the local behaviors of the individual walls and the overall structural performance, respectively. A new analytical approach to obtaining AAF and CR for three different types of lateral loads has been proposed to avoid complex numerical simulations or time-consuming analyses. Firstly, a differential equation with respect to AAF was established using a concise expression of the external moment; AAF calculation method considering triangular, uniform, and top concentrated lateral loads was developed. Secondly, CR calculation formulas for three different types of lateral loads were derived based on the formulas of AAF and applied to simplify the formulas of calculating top lateral deflection of CSWs. Thirdly, the calculation method of AAF, CR and the simplified formulas of top lateral deflection were validated by conducting numerical simulations using ABAQUS and OpenSees. Finally, the advantages of the proposed methods as well as the impact of lateral load types and nonlinearities, etc. were discussed. It was found that AAF and CR could be efficiently calculated by the proposed approach for CSWs including asymmetric ones subjected to three typical lateral loads, and the relative errors compared with numerical simulation are less than 10%. Besides, different types of lateral loads affect the distributions of AAFs and the values of CR.

Enhancing the Seismic Resilience of Steel Moment Resisting Frame with a New Precast Self-Centering Rocking Shear Wall System

In this paper, a new precast self-centering rocking shear wall system (PSCRSW) mainly composed of precast reinforced concrete (RC) wall, V-shaped steel brace and pre-pressed disc spring friction damper (PDSFD) are proposed to enhance the seismic resilience of steel moment resisting frame (SMRF). The mechanical behavior of PDSFD was investigated and simulated. The skeleton model of PSCRSW was theoretically derived and numerically validated, and the hysteretic performance under different design parameters was discussed and compared with that of the conventional RC shear wall. Based on the analyses, design principles and suggestions for PSCRSW were given. Then, an efficient seismic resilient design method for enhancement of SMRF was proposed, which considers performance objectives of multiple seismic hazard levels and has less design iteration. A typical SMRF was adopted as the prototype to be enhanced by the presented PSCRSW and design method. Reliable numerical models for the prototype and the enhanced SMRF were established, and nonlinear dynamic analyses were performed to assess the effectiveness of enhancing strategy. The results show that PSCRSW can realize approximate yielding behavior, displacement capacity and lateral strength to the conventional shear wall and can significantly lower the residual drift and wall damage. During the design, the ratio of preload to friction force for PSCRSW was suggested to be 1.5~2.0, and the bearing capacity for the wall was suggested to be amplified 1.2 times. Thereby, desirable bearing and self-centering performances can be guaranteed. The presented design method is capable of achieving the inter-story drift ratio targets and the expected roof drift ratios simultaneously, and the seismic resilience of the chosen SMRF was significantly improved by a large margin of reduction in residual inter-story drift and frame member damages.

Backbone model for reinforced concrete block shear wall components and systems using controlled multigene genetic programming

Reinforced concrete block shear walls (RCBSWs)have been used as an effective seismic force resisting system in low- and medium-rise buildings for many decades. However, attributed to their complex nonlinear behavior and the composite nature of their constituent materials, accurate prediction of their seismic performance, relying solely on mechanics, has been challenging. This study adopts multi-gene genetic programming (MGGP)— a class of bio-inspired artificial intelligence, to uncover the complexity of RCBSW behaviors and develop simplified procedures for predicting the full backbone curve of flexure-dominated RCBSWs under cyclic loading. A piecewise linear backbone curve was developed using five secant stiffness expressions associated with: cracking; yielding; 80% ultimate; ultimate; and 20% strength degradation (i.e., post-peak stage) derived through mechanics-controlled MGGP. Based on the experimental results of large-scale cyclically loaded fully-grouted RCBSWs, compiled from previously reported studies, a variable selection procedure was performed to identify the most influential variable subset governing wall behaviors. Subsequently, the MGGP stiffness expressions were trained and tested, and their accuracy was compared to that of existing models employing various statistical measures. In addition, the predictability of the developed backbone model was assessed at the system-level against experimental results of two two-story buildings available in the literature. This study demonstrates the power of the MGGP approach in addressing the complexity of the cyclic behavior of RCBSWs at both component- and system-level—offering an efficient prediction tool that can be adopted by relevant seismic design standards pertaining to RCBSW buildings.

Experimental study on cold-formed steel shear walls with different corrugated steel sheathings

Recent research identified the feasibility of adopting corrugated steel sheets as the sheathing material in the cold-formed steel (CFS) shear wall system. However, different experimental results were reported when using different corrugated cross-sections. To determine the effect of different corrugated steel sheathings on the shear capacities of CFS shear walls, this paper conducted an experimental study on the seismic behavior of corrugated steel sheet sheathed shear walls with different cross-section profiles. The selection of corrugated cross-sectional dimensions was informed by the existing research, including corrugated steel sheets with a rib height of 5 mm, 15 mm, and 38 mm. The experiments involved ten full-scale shear wall specimens evaluated under lateral monotonic loading and cyclic loading. The test results indicate that shear walls with 5 mm-rib-height corrugated steel sheets are most likely to produce shear buckling waves, and therefore have the best ductility and highest utilization of sheathing capacity. Shear walls are more apt to screw connection failure and sheathing local buckling as the rib height increases. There is no obvious difference in the shear capacity between the three types of shear walls due to the premature failure of 15 mm- and 38 mm-rib-height corrugated steel sheets. Sheathing buckling was detected and a substantial increase in the shear capacity was achieved when the reduced screw spacing was adopted in the 15 mm-rib-height corrugated sheet sheathed shear walls. The design of corrugated steel sheet sheathed shear walls needs to consider the influence of both the corrugation and screw arrangement.

A Numerical Investigation on the Limitations of Design Equations for Steel Plate Shear Walls

In previous studies various design issues on steel plate shear wall (SPSW) systems under lateral loading were investigated using analytical and experimental methods. However, these studies tried to examine the interactive effect of only a few of design parameters, such as panel aspect ratio, column flexibility parameter, axial load ratio on the boundary frame columns, web plate thickness, stiffness of horizontal and vertical boundary elements and top anchor beam, etc., on the drift capacity and shear force distribution among frame and panel components of SPSWs at a time. This study investigates the effect of all of these parameters in the same framework. A parametric study is conducted on finite element models of 292 3-story SPSWs with rigid beam-to-column connections and designed for specified parameters. By evaluating failure forms from finite element analyses, the limiting (undesired) cases resulting from different combinations of specified geometric properties are identified. A column flexibility factor of 2.2 is proposed instead of the current limit value of 2.5 for satisfactory column performance, improved drift capacity and balanced strength distribution among frame and panel of SPSW. The value of 0.75 for the ratio of plate shear force to total shear force has emerged as a critical threshold value for the strength distribution among plate and frame components in order to conform capacity design principles. This study provides a comprehensive look on the behavior of SPWS for determining the most suitable combination of various parameters in the design of SPSW structures.

Shake table tests of a corrugated steel sheathed cold-formed steel structure

The corrugated steel sheathed cold-formed steel (CFS) shear wall is an innovative lateral force-resistant system with excellent potential for development. Many research has been conducted on the seismic behavior of this innovative shear wall system. However, dynamic properties as well as the failure mechanism of the CFS structures with corrugated steel sheathing are still unclear. This study aimed to increase knowledge of the seismic performance of CFS structures through the shaking table test, of which the seismic force resisting system was provided by corrugated steel sheathed shear walls. Importantly, this test also took into account the extremely rare precautionary intensity. The main results indicated that damage of CFS structure began to occur in the walls and floors under rare earthquakes and increased further with the seismic intensity. The final damage primarily occurred through the failure of connections and inner panels under extremely rare precautionary intensity. The degree of variation in the dynamic properties of the structure increased further as the damage accumulated. In particular, the damping ratio of the structure in the non-linear phase ranged from 5% to 7.5%. It was unreasonable to assume that the trend of the acceleration amplification factor with structural height was determined as a linear relationship. The peak inter-story drift ratio of the corrugated steel sheathing CFS structure could meet the multi-level seismic precaution requirements of the code. Finally, the seismic performance parameters of the CFS structure were evaluated by numerical simulations. This research will provide a reference for the seismic design of CFS structures under extremely rare conditions.

Seismic performance of high-capacity light wood frame shear walls with three rows of nails

With the increase of building height for light wood-frame construction and seismic loads in National Building Code of Canada 2015, stronger shear wall systems have been facing higher demands, especially for mid-rise wood-frame buildings located in high seismic zones. In collaboration with FPInnovations, a new high-capacity shear wall system with two or three rows of nails was developed. This paper presents the test results of shear walls with three rows of nails. A total of 12 specimens (with two standard shear wall specimens as a reference) were tested under reversed cyclic loading. Test results show that shear walls with three rows of nails have approximately-three times the lateral load resistance of a standard shear wall with the same sheathing thickness, nail diameter and nail spacing. The initial stiffness and ultimate displacement of the high-capacity shear wall are also greater than the comparable standard shear wall. Seismic equivalency to standard shear walls in accordance with ASTM D7989 was also conducted. Although shear walls with three rows of nails have three times of lateral load capacities of a standard shear wall, their design values are less than twice the design values of the standard shear walls. This is mainly due to the fact that a higher over-strength factor has to be used to meet the ductility criteria in ASTM D7989.

Test, Analysis, and Seismic Design Approach of RC Infill Walls Isolated by PVC Tubes in Coupled Shear Wall Systems

Test, Analysis, and Seismic Design Approach of RC Infill Walls Isolated by PVC Tubes in Coupled Shear Wall Systems

Simplified Design of Coupled Shear Wall Systems for Typical Building Configuration

Simplified Design of Coupled Shear Wall Systems for Typical Building Configuration

Farklı Dolgu Tipleri için Çerçevelerin İtme Analizi ile Kıyaslanması

Earthquake-resistant building design is becoming increasingly important as a result of destructive earthquakes. Earthquake, which is a natural event that occurs as a result of geological movements, can turn into a natural disaster according to the behavior of the structures under the influence of earthquakes. In this study, a reinforced wall model was compared with other frame types in order to reduce the earthquake effect on the structures. With this reinforced wall model, the building is intended to be more ductile than shear wall systems and more rigid than bare frame systems. Static Pushover Analysis, which is currently and widely used, was used within the scope of performance-based design. The pushover analysis method is explained in detail and applied to all models. Single-storey frame models in order to make comparisons with the analyzes; The frame modeled with bare frame, shear wall frame and reinforced wall model has two different types, 15x15 and 20x20 ( in centimeters) , in total, 4 models. These models were compared and interpreted in terms of ductility and stiffness.

Assessment of cyclic behavior and performance of hybrid linked-column steel plate shear wall system

An innovative hybrid linked columns steel plate shear wall (HLCS) system provided, and its cyclic behavior and energy absorption are investigated by finite element method in this study. The objective of the designed HLCS system was to reduce or possibly prevent damage to the SPSW at low and medium seismic levels by focusing the seismic damage to interchangeable link beams (the energy dissipation components of the presented HLCS system). In this study, the cyclic behavior and energy dissipation of HLCS systems were investigated using numerical methods. To evaluate the hysteresis behavior and energy absorption of the proposed HLCS system, parametric studies were performed. Also, the accuracy of finite element models was evaluated by comparing test results that showed the good accuracy of finite element models in predicting the specimens' hysteresis behavior and failure modes. Due to the failure mechanisms, the coupling ratio amounts meaningfully affect the onset of the first surrender mechanism between the infill steel plate and link beams. In general, by increasing the number of link beams in the floor, the ultimate shear force to the weight ratio of the structure was increased. Also, the type of beam in terms of flexural and shear behavior did not significantly affect the ratio of base shear force to the structure weight. The proposed HLCS system has increased the ratio of base shear force to the weight by an average of 4%–27%, indicating that this system is economically comparable to the SPSW systems. Moreover, the energy dissipation in the HLCS system exhibited a 14%–91% enhancement compared to the SPSW system.

Study on Vertical Joint Performance of Single-Faced Superposed Shear Wall Based on Finite Element Analysis and Calculation.

In this paper, a new type of single-faced superposed shear wall system is proposed based on the single-faced superposed shear wall structure. The nonlinear finite element analysis of a new splicing form of single-faced superposed shear wall components is carried out by using the method of combining experimental research and ABAQUS finite element software analysis. The impact of noncolumn on the connection performance of vertical seam is studied. The analysis shows no significant difference in the effect of eliminating concealed column on the hysteretic performance and bearing capacity of the single-faced superposed shear wall with the joint. The single-faced composite shear wall with two different splicing forms presents bending-shear failure. The single-faced composite shear wall model without concealed column design can also maintain good overall performance and seismic behavior.

Experimental and numerical study of concrete frames with steel plate shear walls

Steel plate shear wall systems have appropriate behavior in high seismic zones. They could be combined with concrete or precast concrete structures to compensate susceptibility of these structures to strong earthquakes. This article presents an experimental and numerical study on seismic behavior of various types of steel plate shear walls installed in simple and rigid concrete frames. These frames were subjected to quasi-static cycling loading in accordance with ACI T1.1–01. Compared to the bare moment frame, erection of the steel plate in simple concrete frame by bearing bolted connection led to an increase in lateral load capacity, initial stiffness, energy dissipation and equivalent hysteretic damping up to 1.7, 2.2, 3.5 and 3 times, respectively. These ratios for the steel plate shear wall with moment frame, and connected by friction bolted connections were 3, 7.2, 7.7 and 3.2 times. The horizontal and vertical stiffeners in the steel plate shear wall with the openings over the main diameters contributed to 13% and 27% increase in energy dissipation and equivalent damping, respectively, while the load bearing capacity and initial stiffness did not decrease significantly. At the bearing bolted connections, crippling and tearing of the steel plate was observed, but no any damage occurred at the friction bolted connections. Whereas, all the steel connecting components embedded in concrete were in the elastic range and also, equations governing the angle of inclination of the tensile field, were valid. Finally, the samples were simulated in Abaqus finite element software, and the pushover curves of experimental load-displacements diagrams were predicted.

An experimental study of the mechanical behaviour of squat shear walls built with precast concrete two-way hollow slabs

This paper proposes an innovative precast shear wall system built with precast concrete two-way hollow slabs (PCHS shear walls). In the joints of the precast panels of the PCHS shear walls, noncontact lap splices of rebars with vertical and horizontal holes are used to connect adjacent precast panels. These panels contribute to an automated assembly and facilitate pouring concrete in-situ. The mechanical behaviour of PCHS shear walls and the connection performance of vertical joints are examined through pseudo-static loading testing on one cast-in-situ concrete shear wall and four PCHS shear walls. Moreover, the influences of different parameters, including axial compression ratio, aspect ratio and the magnitude of horizontal distribution reinforcements, were analysed. It was found that the "strong bending and weak shear" requirement was achieved for all specimens. For the PCHS shear walls, the typical prominent diagonal cracks and brittle failure were prevented by the shear slippage at vertical joints and vertical cracks. And the vertical joint enabled the PCHS shear walls to exhibit stable load-bearing capacity with extensive deformations. In addition, the displacement ductility coefficient of all PCHS shear walls was over 5.0, and their ultimate drifts were over 1/100. The bearing capacity was improved with the increase of the axial compression ratio or with the decrease of the aspect ratio, but the deformation capacity was weakened.

Experimental seismic behaviors of different connections to CFST end-columns in shear walls

A new hot-rolled T-shaped connector (HTC) connection was proposed herein to solve the connecting difficulties between H-shaped beams and small-sized composite walls or CFST columns in steel residential buildings. The connection utilizes the hot rolled flange-to-web arch transition in hot rolled beams as the beam-end connector. In this way, the hot-rolled arch transition of the connector provides a smooth section transition at the column face junction to avoid stress concentrations and premature fracture problems in traditional welded junctions. The new connections, together with the existing endplate type and side plate type connections, were applied to a specially-shaped corrugated plate shear wall system. Seismic loading tests were performed to explore seismic behaviors and the applicability of those connections in steel residential buildings. Results indicated that the side plate connections and HTC connections exerted good hysteretic performance with stable hysteretic behaviors, slow stiffness degradation, good energy dissipation ability, and satisfactory ductility. The endplate connection experienced early fracture failure of the side plate to endplate welds. In addition to the satisfactory seismic performance, the proposed HTC connections had no extended stiffeners and little intrusion into the indoor space, and could be easily hidden within partition walls.

Probabilistic Seismic Assessment of CoSPSW Structures Using Fragility Functions

The corrugated steel plate shear wall (CoSPSW) is a new type of steel plate shear wall, in which corrugated wall plates instead of flat wall plates are adopted. The lateral stiffness and shear buckling capacity of the shear wall system could be significantly enhanced, and then, wall plate buckling under gravity loads would be mitigated. This paper presents a study on the probabilistic assessment of the seismic performance and vulnerability of CoSPSWs using fragility functions. The damage states and corresponding repair states of CoSPSWs were first established from experimental data. Then, incremental dynamic analyses were conducted on the CoSPSW structures. The structural and nonstructural fragility functions were developed, based on which the seismic performance and vulnerability of the CoSPSWs were obtained and compared with the conventional steel plate shear walls (SPSWs). It was shown that for various repair states, the 25th percentile PGA of the CoSPSW was always higher than the SPSWs with the same wall thickness and boundary frame, which indicated that the CoSPSW has a lower damage potential and better seismic performance than the SPSW.

Retrofitting of Core Reinforced Concrete Shear Wall System with Opening Using Steel Plates and FRP Sheets, A Case Study

Retrofitting of Core Reinforced Concrete Shear Wall System with Opening Using Steel Plates and FRP Sheets, A Case Study

Experimental and numerical investigation on seismic performance of semi-precast concrete sandwich shear wall

This study investigated the seismic performance of an innovative semi-precast concrete sandwich shear wall (SCSSW) system. The system consists of two precast reinforced concrete (RC) wythes, a core cast-in-place RC wythe, a core thermal insulation layer, the fiber reinforced polymer connectors and the steel trusses. A total of three RC shear wall specimens were fabricated and tested under in-plane cyclic load. They consists of one conventional cast-in-place RC shear wall, one structural wythe of SCSSW (i.e., the assemble of a precast and a cast-in-place RC wythe), and one typical SCSSW. The failure mode, hysteretic curve, ductility and energy dissipation of the three specimens were studied and compared. Furthermore, numerical simulation based on multi-layer shell element was conducted to reproduce the test, and parametric analysis was conducted to facilitate a better understanding on the SCSSW. It was concluded that the SCSSW presented a ductile failure behavior; the seismic performance of the SCSSW including hysteretic curves, skeleton curves, stiffness degradation and the energy dissipation was similar to that of the cast-in-place RC shear wall, while the ductility of the SCSSW was slightly lower; and the facade precast RC wythe contributed few effect on the seismic performance of the SCSSW.