Self-centering Energy Dissipation Research Articles

Development and experimental validation of a steel plate shear wall with self-centering energy dissipation braces

Abstract A new type of steel plate shear wall with self-centering energy dissipation braces (SPSW-SCEDB) was developed. Validation tests of the wall plate and the pre-pressed spring self-centering energy dissipation (PS-SCED) braces were conducted and a single-bay, single-story, 1:3-scale SPSW-SCEDB specimen was designed, fabricated, and tested under cyclic loadings. The results demonstrated that the SPSW-SCEDB exhibited a stable flag-shaped hysteretic response with high initial stiffness, appreciable ductility, and excellent self-centering and energy dissipation capabilities due to the synergistic effects of the wall plate and the PS-SCED braces. The proposed theoretical equations of the compressive force of the wall plate, the ultimate lateral load capacity, and the remaining restoring force of the SPSW-SCEDB were verified. The PS-SCED braces reduced the stiffness degradation of the wall plate and improved the lateral force resistance and the stability of the SPSW-SCEDB system. The wall plate provided more energy dissipation than the PS-SCED braces. The remaining restoring force of the PS-SCED braces should be as small as possible to maximize the energy dissipation of the PS-SCED braces while ensuring that it overcomes the compressive force of the wall plate.

Experimental study on component performance in steel plate shear wall with self-centering braces

Steel plate shear wall with self-centering energy dissipation braces (SPSW-SCEDB) is a lateral force-resisting system that exhibits flag-shaped hysteretic responses, which consists of two pre-pressed spring self-centering energy dissipation (PS-SCED) braces and a wall plate connected to horizontal boundary elements only. The present study conducted a series of cyclic tests to study the hysteretic performances of braces in SPSW-SCEDB and the effects of braces on the overall hysteretic characteristics of this system. The SPSW-SCEDB with PS-SCED braces only exhibits excellent self-centering capability and the energy loss caused by the large inclination angle of PS-SCED braces can be compensated by appropriately increasing the friction force. Under the combined effect of the two components, the SPSW-SCEDB exhibits a flag-shaped hysteretic response with large lateral resistance, good energy dissipation and self-centering capabilities. In addition, the wall plate is the primary energy dissipation component and the PS-SCED braces provide supplementary energy dissipation for system. The PS-SCED braces can provide up to 90% self-centering capability for the SPSW-SCEDB system. The compressive bearing capacity of the wall plate should be smaller than the horizontal remaining restoring force of the braces to achieve better self-centering effect of the system.

Seismic Assessment of Buildings with Prepressed Spring Self-Centering Energy Dissipation Braces

AbstractThe seismic performance of four- and eight-story steel buildings with prepressed spring self-centering energy dissipation (PS-SCED) braces was evaluated using a proposed nonlinear mechanica...

Seismic performance evaluation of steel frames with pre-pressed spring self-centering braces

Pre-pressed spring self-centering energy dissipation (PS-SCED) braces with flag-shaped hysteretic responses are expected to undergo large deformation while re-centering to their origin, providing a self-centering capability for the structures. Three 4-, 8-, and 16-story braced frames with PS-SCED braces were analyzed to assess their seismic performances in comparison to conventional steel braced frames (CSBFs) and buckling restrained braced frames (BRBFs). Detailed analytical models of the PS-SCED braces were implemented and seven suites of ground motions with three different hazard levels were used to assess the structural performances with respect to interstory drifts, residual deformations, and peak floor accelerations during earthquakes. It was shown that the CSBFs underwent larger average responses than the BRBFs and the PS-SCED braced frames. The interstory drifts and peak floor acceleration responses of the frames with the BRBs were comparable and often better than those of the frames with the PS-SCED braces due to their high energy dissipation and simpler hysteretic cycles; the difference in the performance of these two braces tended to decrease with the increase in the seismic hazard level and the building height. The PS-SCED braces reduced the residual deformations more effectively than the BRBs and CSBs.

Behavior and Design of Self-Centering Energy Dissipative Devices Equipped with Superelastic SMA Ring Springs

AbstractThis paper presents a novel type of self-centering energy dissipative device equipped with superelastic shape memory alloy (SMA) ring springs. The fundamental mechanical behavior and analyt...

Numerical analysis of self-centering energy dissipation brace with arc steel plate for seismic resistance

A self-centering energy dissipation brace (SEDB) with an arc steel plate was designed to improve the seismic performance of a structure and reduce the residual structural deformation after an earthquake. Seven groups of self-centering energy dissipation brace models of arc steel plates with different configurations were established based on ABAQUS software. A method for calculating the internal forces, stiffness, yield displacement and yield load of a brace was derived and shows agreement with theoretical values. This brace shows a favorable hysteretic performance that corresponds to its full, flag-shaped hysteretic curve. The stiffness transition of various stages is smooth and stable. The maximum residual deformation of the component is 3.75 mm and decreases as prepressing of the disc springs is increased. The component's reset performance can be fully utilized to satisfy specific needs. The advised values for designing the energy dissipation components of an arc steel plate are described as follows: 1/250 of a radian, width of 50–80 mm and thickness of 20 mm. The damping force, damping displacement and brace stiffness of the SEDB can be adjusted by the structural parameters of the arc steel plate to satisfy the engineering requirements.

Seismic Retrofitting Effects of General Hospital Using Self-Centering Energy Dissipative Bracing System

Seismic Retrofitting Effects of General Hospital Using Self-Centering Energy Dissipative Bracing System

Seismic performance of framed underground structures with self-centering energy-dissipation column base

For the development of underground structures toward large-scale, long-span, and complex structural styles, comprehensive seismic mitigation and controlling measures that consider reducing internal forces together with controlling lateral structural deformation and upgrading energy consumption are significant for improving seismic performance and enhancing resilience of underground structure. For this purpose, a self-centering energy-dissipation column base, which originated from the concept of earthquake resilient structures in aboveground space, is proposed for the framed underground structures in this study. To verify the effectiveness of self-centering energy-dissipation column base, three-dimensional time history analyses are conducted on a single-story double-span subway station. The analysis results show that the self-centering energy-dissipation column base effectively decreases the internal forces of central column and the peak and residual values of story drift and column drift are also minimized about 4%–5%. Meanwhile, it is found that a cyclic opening–closing exists at the column base during an earthquake and the uplift of column returns to zero at the end of the earthquake. It means the self-centering effect of the column base is achieved as expected. Moreover, replaceable energy-dissipating devices provide supplementary energy dissipation to relieve the development of structural plasticity and the uplift behavior of column base avoids the occurrence of plastic hinge. As a result, the structural damages are effectively reduced after the earthquake.

Hysteresis analysis of pre-pressed spring self-centering energy dissipation braces using different models

The ability of an idealized piecewise-linear restoring force model and a nonlinear mechanical model to describe the hysteretic performances of the pre-pressed spring self-centering energy dissipation braces was evaluated based on experimental data. The hysteretic behaviors predicted by these two proposed models were compared with the experimental results of a typical prototype brace, and the results demonstrated that the two models can explain the brace force-time responses, and that the nonlinear mechanical model is more effective in describing the stiffness transition and energy dissipation of the brace. The two proposed models can be used for the design of the pre-pressed spring self-centering energy dissipation brace specimens, and the nonlinear mechanical model may be more useful for designing the structures with the pre-pressed spring self-centering energy dissipation braces. An orthogonal experiment was applied to analyze the influences of the key parameters on the performances of pre-pressed spring self-centering energy dissipation braces based on the nonlinear mechanical model. The results indicate that the friction slip force of energy dissipation mechanism, the pre-pressed force of self-centering mechanism, and the post-activation stiffness significantly affect the hysteretic performances and equivalent viscous damping ratios of the bracing system, while the changes in other parameters only produce slight effects. The determination of the pre-pressed force of the self-centering mechanism should be coordinated with the friction slip force of the energy dissipation mechanism to achieve a better hysteretic performance of the pre-pressed spring self-centering energy dissipation brace.

Probabilistic Assessment of Upgraded Rocking Cores-Moment Frames with Supplemental Self-Centering Energy Dissipation Devices

ABSTRACT An upgraded rocking cores-moment frame (RCMF), aimed to improve the RCMF from life safety to seismic resilience, is proposed in this article by equipping the rocking cores with replaceable self-centering energy dissipation devices. Its seismic performance is assessed within a probabilistic framework, which treats maximum interstory drift ratio (MD) and residual interstory drift ratio (RD) as a combined engineering demand parameter. Results indicate that the upgraded RCMF demonstrates an outstanding performance in reducing MD, RD and their corresponding deviations, mitigating the drift concentration, especially in eliminating the RD, which highlights its potential to achieve seismic resilience.

Seismic responses of steel frame structures with self-centering energy dissipation braced on shape memory alloy cables

Shape memory alloys have attracted a great deal of attention in civil engineering due to their excellent super elastic and moderate energy dissipating capabilities. At present, the shape memory alloy cables have been developed to meet the large size demand for practical applications. This article carries out numerical studies on the seismic responses of the steel frame with self-centering energy dissipation braced on shape memory alloy cables (SMA-SCEB) using OpenSees. The mechanical properties of the shape memory alloy cables were experimentally investigated first and compared to the traditional shape memory alloy wires/bars. Experimental results show the excellent super-elastic property of the shape memory alloy cables. A SMA-SCEB device is then proposed, and quasi-static cyclic loading tests are performed to evaluate its hysteretic behavior. The SMA-SCEB device is installed in the steel frame structure to enhance its seismic performances. Nonlinear dynamic analyses are carried out to examine its seismic responses. For comparison, the performance of self-centering energy dissipation brace with pre-tensioned basalt fiber–reinforced polymer cables (BFRP-SCEB) is also studied. Numerical results demonstrate that the self-centering energy dissipation brace can significantly reduce the residual drift ratio of the structure. In particular, the steel frame structure equipped with SMA-SCEBs suffers smaller peak acceleration than the one with the BFRP-SCEBs.

Seismic performance and damage analysis of RC frame–core tube building with self-centering braces

This paper examines the seismic responses of a reinforced concrete (RC) frame–core tube building with pre-pressed spring self-centering energy dissipation braces (PS-SCEDBs). The PS-SCEDB is a passive energy dissipation device with disc springs and friction pads. Parameters of PS-SCEDBs installed on the structure are designed according to the principle of equivalent stiffness, based on the parameters of a buckling-restrained brace (BRB) equipped on the original RC frame–core tube structure. The constitutive models of self-centering flag-shaped and bilinear elastoplastic hysteresis for PS-SCEDBs and BRBs, respectively, are developed and experimentally verified. The seismic performance of RC frame–core tube structures with PS-SCEDBs and BRBs, respectively, are studied and compared using non-linear time history analysis. Results show that the PS-SCEDB can substantially reduce residual drift ratios of a concentrically braced building while still capable of effectively controlling the peak inter-story drift ratio and damage of components adjacent to braces under rare earthquakes. The structure with PS-SCEDBs can effectively dissipate seismic energy without increasing damage to beams, columns, and shear walls.

Application of self-centering wall panel with replaceable energy dissipation devices in steel frames

The self-centering capacity and energy dissipation performance have been recognized critically for increasing the seismic performance of structures. This paper presents an innovative steel moment frame with self-centering steel reinforced concrete (SRC) wall panel incorporating replaceable energy dissipation devices (SF-SCWD). The self-centering mechanism and energy dissipation mechanism of the structure were validated by cyclic tests. The earthquake resilience of wall panel has the ability to limit structural damage and residual drift, while the energy dissipation devices located at wall toes are used to dissipate energy and reduce the seismic response. The oriented post-tensioned strands provide additional overturning force resistance and help to reduce residual drift. The main parameters were studied by numerical analysis to understand the complex structural behavior of this new system, such as initial stress of post-tensioning strands, yield strength of damper plates and height-width ratio of the wall panel. The static push-over analysis was conducted to investigate the failure process of the SF-SCWD. Moreover, nonlinear time history analysis of the 6-story frame was carried out, which confirmed the availability of the proposed structures in permanent drift mitigation.

Seismic damage mitigation of bridges with self-adaptive SMA-cable-based bearings

Residual drifts after an earthquake can incur huge repair costs and might need to replace the infrastructure because of its non-reparability. Proper functioning of bridges is also essential in the aftermath of an earthquake. In order to mitigate pounding and unseating damage of bridges subjected to earthquakes, a self-adaptive Ni-Ti shape memory alloy (SMA)-cable-based frictional sliding bearing (SMAFSB) is proposed considering self-adaptive centering, high energy dissipation, better fatigue, and corrosion resistance from SMA-cable component. The developed novel bearing is associated with the properties of modularity, replaceability, and earthquake isolation capacity, which could reduce the repair time and increase the resilience of highway bridges. To evaluate the super-elasticity of the SMA-cable, pseudo-static tests and numerical simulation on the SMA-cable specimens with a diameter of 7 mm are conducted and one dimensional (1D) constitutive hysteretic model of the SMAFSB is developed considering the effects of gap, self-centering, and high energy dissipation. Two types of the SMAFSB (i.e., movable and fixed SMAFSBs) are applied to a two-span continuous reinforced concrete (RC) bridge. The seismic vulnerabilities of the RC bridge, utilizing movable SMAFSB with the constant gap size of 60 mm and the fixed SMAFSBs with different gap sizes (e.g., 0, 30, and 60 mm), are assessed at component and system levels, respectively. It can be observed that the fixed SMAFSB with a gap of 30 mm gained the most retrofitting effect among the three cases.

Development and validation tests of an assembly self-centering energy dissipation brace

This investigation develops and experimentally studies an assembly self-centering energy dissipation (ASCED) brace that consists of an energy dissipation device composed of friction pads, a self-centering device composed of disc springs, and bracing members. The ASCED brace has attractive assembly and adjustment abilities and uses simple mechanics. Cyclic test results of the energy dissipation device demonstrated that it had stable energy dissipation capability without deterioration of the friction pads or loosening of the high-strength bolts. A large-scale ASCED brace specimen was designed, fabricated, and tested under cyclic loadings, and the results verified the adjustability of the ASCED brace and confirmed the cooperation performance of the energy dissipation device and the self-centering device. Repeatable flag-shaped hysteretic responses and a smooth transition of stiffness between different stages were observed. These results demonstrated the favorable seismic performance of the brace. The residual deformation was negligible when the pre-pressed force of disc spring was greater than the friction force provided by the energy dissipation device.

Cyclic behaviors of steel plate shear wall with self-centering energy dissipation braces

The present study develops and numerically verifies a new type of earthquake resilient system. The proposed system combines a steel plate shear wall with infill panel connected to beams only and pre-pressed spring self-centering energy dissipation (PS-SCED) braces that provide the self-centering and additional energy dissipation capabilities. The mechanics of this system is explained and the equations governing its stiffness and strength are also presented. A simplified model is proposed to simulate the hysteretic behaviors of the PS-SCED braces, and comparisons with experimental results demonstrate that the proposed model can effectively describe the hysteretic responses of the bracing system. The hysteretic behaviors of the proposed system and the effects of the infill panel and the PS-SCED braces parameters on the system performance under cyclic loadings are analyzed. Results indicate that the proposed system exhibits a flag-shaped hysteretic response with large stiffness, high strength, excellent self-centering and energy dissipation capabilities. The initial stiffness and yield force of the system are well predicted by the governing equations. The energy dissipation capability of the system is mainly affected by the PS-SCED braces, and the system with the self-centering ratio of 0.7 or more can limit the residual deformation to the tolerance for new steel building when the inter-story drift ratio reaches 2%.

Behavior and design considerations of steel plate shear wall with self-centering energy dissipation braces

An innovative steel plate shear wall with self-centering energy dissipation braces (SPSW-SCEDB) is proposed, and the mechanical behavior is explained. The system has excellent self-centering capability when the remaining restoring force of the braces is greater than or equal to the compressive force of the wall plate. On the basis of capacity design principles, the distribution equations of bending moment, axial force, and shear force along the beam are developed and then verified by cyclic loading analysis. The effects of the SPSW–SCEDB parameters on the bending moment distribution are investigated using an orthogonal experiment and the sequence of plastic hinge appearance in the beam is also analyzed. Results indicate that to satisfy the strength and residual deformation requirements of the system, the initial force of the brace and the thickness of the wall plate should be sufficiently large, and the brace activation force should be controlled to ensure that the plastic hinge in the beam appears before the in-span plastic hinge. The design procedure of the SPSW-SCEDB is presented.

Behaviors Comparisons and Prediction of Pre-Pressed Spring Self-Centering Energy Dissipation Braces

The pre-pressed spring self-centering energy dissipation (PS-SCED) brace that combines the friction energy dissipation mechanism with a self-centering member comprising combination disc springs is developed and experimentally studied. The configuration of the proposed bracing system is presented and a Bouc–Wen model-based restoring force model is proposed to predict its hysteretic behavior. Two large scale PS-SCED braces with different length and different types of disc springs are designed, fabricated, and tested under low cyclic reversed loadings, and results demonstrate that the PS-SCED brace exhibits stable and repeatable self-centering hysteretic responses with effective energy dissipation capacity. The ductility of the proposed bracing system can be enhanced by employing the disc springs with bearing surface, and increasing the length of the tube members or segments of the disc springs. The symmetry of the bearing force in tension and in compression meets the design requirement for bracing elements. And the proposed restoring force model can accurately portray the hysteretic behavior of the PS-SCED bracing system.

Research and development of an innovative self‐centering energy dissipation brace

SummaryInnovative self‐centering energy dissipation braces (SCBs) with super‐elastic shape memory alloy wires are designed and tested on a uniaxial MTS 810 hydraulic servo‐controlled fatigue testing machine. This type of SCB is modeled using finite element method and analyzed by ANSYS software. The test and analysis results show that this type of innovative SCB possesses energy dissipation capacity and self‐centering ability. This paper also describes the multistage working mechanism of the SCBs and exhibits the mechanical behaviors of the braces. The hysteretic behavior of steel frame structures with conventional braces, the buckling‐restrained braces, and the SCBs are compared by conducting low‐frequency cyclic loading. Nonlinear dynamic analyses of steel frame structures with the conventional braces, the buckling‐restrained braces, and the SCBs under frequently occurred earthquake, design basis earthquake, and rare earthquake, respectively, are also performed to compare the seismic responses of steel structures with different braces. The seismic behaviors of these frames are investigated by comparing the peak acceleration, the maximum interstory displacement angle, and the maximum base shear. The results show that the innovative SCB possesses excellent energy dissipation capacity as well as self‐centering ability. Additionally, the innovative SCBs can effectively control the seismic response of the steel frame structure.

Hysteretic Analysis Model for Pre-pressed Spring Self-Centering Energy Dissipation Braces

AbstractA restoring force model is proposed that is applicable for predicting the hysteretic behaviors of the pre-pressed spring self-centering energy dissipation (PS-SCED) braces. Two Bouc-Wen mod...