Self-centering Damper Research Articles

Comparative seismic performance evaluation of friction, self-centering and hybrid self-centering dampers

This study explores comparative seismic performance of a shape memory alloy (SMA)-only device, a friction damper, and a hybrid self-centering device. The self-centering device considered in this study, named as superelastic friction dampers (SFDs), is a hybrid damper operating on a mechanism where SMA cables and frictional components are arranged in parallel. A detailed description of the device and an experimental characterization of mechanical behavior are presented first. Then, an 8-story archetype steel frame building is designed and modeled with each seismic protection device (SMA-only, hybrid self-centering, and friction only). To enable comparative performance assessment, each device is designed to have similar initial stiffness and the same maximum force at design displacement. Nonlinear time history analyses are conducted using a total of 44 ground motion records. The results are evaluated to compare performance of each frame design at design-basis and maximum considered earthquake hazard levels. Next, a risk-based seismic hazard demand analysis framework that involves comprehensive incremental dynamic analyses is employed for further assessing the performance of each system. The experimental results validate the parallel working mechanism of SMA cables and frictional components in the SFD, with 90% of the damper deformations recovered. Comparative analysis of seismic responses demonstrates the excellent performance of the SFDs in reducing interstory drift ratio, residual interstory drift ratio, and absolute acceleration responses. Furthermore, fragility analysis and risk-based seismic hazard assessment further reveal that the SFDs provide a well-balanced combination of energy dissipation capability and self-centering ability, thereby enhancing the seismic resilience of structures.

Design and Hysteretic Performance Analysis of a Novel Multi-Layer Self-Centering Damper with Shape Memory Alloy

This paper presented the development process of a novel multi-layer self-centering damper utilizing a NiTi shape memory alloy (SMA) with remarkable superelastic properties. The construction and operating principles of the novel damping device were introduced. A model for calculating the restoring force–displacement hysteretic curve of the novel damper was established, and based on this theoretical model, a parameter analysis of the damper’s hysteresis performance was conducted. The effect of SMA pre-strain, SMA diameter, number of layers in the damper, and number of SMA wires per layer on the damper’s stiffness, the unit cycle energy dissipation, and the equivalent viscous damping ratio were investigated, respectively. The results showed that the restoring force–displacement hysteretic curve of the novel SMA damper exhibits a full spindle shape, demonstrating the damper’s excellent energy dissipation capacity, self-centering capability, significant stroke, and unique variable stiffness characteristics (i.e., appropriate initial stiffness, minimal isolation stiffness, and significant limit stiffness). The results also indicated that the SMA pre-strain has a minor impact on the damper’s stiffness but a significant influence on unit cyclic energy dissipation and equivalent damping ratio. As the SMA pre-strain increased from 0.03 to 0.04, 0.05, and 0.06, the maximum stroke of the damper continuously decreases, while the unit cyclic energy dissipation initially increases and then decreases, with the optimal energy dissipation achieved at a pre-strain of 0.04. Increasing the SMA diameter results in a higher damper stiffness and energy dissipation capacity, with no significant change in maximum stroke and equivalent damping ratio. Increasing the number of damper layers leads to an increase in maximum stroke and unit-cycle energy dissipation, accompanied by a decrease in stiffness and almost constant equivalent damping ratio. As the number of SMA wires per layer increased from 8 to 16 and 32, the maximum stroke and equivalent damping ratio presented little variation, but the damper’s stiffness and unit cyclic energy dissipation continuously increased.

A hybrid self-centering seismic damper: Finite element modeling and parametric analysis

This study presents a finite element model for a hybrid self-centering damper considering the rate and temperature effects and explores the effects of different design parameters on the damper response. The damper, called as superelastic friction damper (SFD), consists of superelastic shape memory alloy (SMA) cables and a frictional energy dissipation mechanism. The experimental response of the SMA cables, frictional unit and overall damper at different loading frequencies and temperature are used to develop numerical model of the damper. Once a validated numerical model is obtained, parametric studies are carried out to evaluate force-displacement response of the damper when the design parameters are altered. The effects of damper design parameters on the equivalent stiffness, dissipated energy, equivalent viscous damping and self-centering capabilities of the damper are analyzed. Based on the findings, the recommendations for the design of the damper are presented.

Development and verification of a variable friction self-centering damper

The structure of a variable friction self-centering damper (VFSCD) and the main key parameters for controlling its hysteretic performance are introduced. The performance evaluation index and calculation method of each index of the VFSCD are defined. The theoretical equation and simulation model of the VFSCD are established and compared with the test results. Based on the verified simulation model, the local behavior and stress mechanism of the key components of the VFSCD are further analyzed. The results show that the VFSCD hysteresis curves are full and have good energy dissipation capacity, and there is no residual deformation or damage to each component after unloading. With the increase in the number of wedge groups, the yield load, loading stiffness and bearing capacity of the VFSCD increase significantly, and the unloading stiffness and restoring force decrease obviously. Importantly, the test curve, the theoretical curve, and the finite element hysteresis curve are in good agreement. Although there are some errors in the test results, the theoretical curves are basically consistent with the simulation curves. The simulation model established in this research can effectively reflect the local behavior and stress mechanism of VFSCD.

Research on the Mechanical Model and Hysteresis Performance of a New Mild Steel-Rotational Friction Hybrid Self-Centering Damper.

A mild steel-friction self-centering damper with a hybrid energy-dissipation mechanism (MS-SCFD) was proposed, which consisted of a mild steel, frictional, dual-energy-dissipation system and a disc spring resetting system. The structure and principle of the MS-SCFD were explained in detail while the restoring force model was established. The hysteretic behavior of the MS-SCFD under low-cycle reciprocating loading was modeled. Then, the influence of parameters such as the disc spring preload, the friction coefficient, and the soft-steel thickness on the mechanical properties of the MS-SCFD was investigated. The results indicate that the simulation results are basically consistent with the theoretical prediction results, with a maximum error of only 9.46% for the key points of bearing capacity. Since the MS-SCFD is provided with a hysteretic curve in the typical flag type, it will obtain the capacity of excellent self-centering performance. It can effectively enhance the stiffness, bearing capacity, and self-centering capability of the damper after the pre-pressure of the disc spring is increased. The energy-dissipation capacity of the MS-SCFD increases with the increase in the friction coefficient. However, it also increases the residual deformation of the MS-SCFD. The energy dissipation of the MS-SCFD is particularly sensitive to the thickness of mild steel. After being loaded, all components of the MS-SCFD are not damaged except for the plastic deformation caused by the yielding of the mild steel. The normal function of the MS-SCFD can be restored simply by replacing the mild steel plates after the earthquake. Therefore, it can significantly enhance the economy and applicability of the damper.

Mechanical characteristics of a novel variable friction hybrid self-centering damper

A novel variable friction hybrid self-centering damper (VFHSCD) with significant self-centering and hysteretic energy-dissipating performance is proposed for resilient structures. This VFHSCD is composed of a novel variable friction self-centering device and an auxiliary restoring system, which is desired to alleviate the conflicting problem in designing the self-centering and friction energy dissipation performance of the existing variable friction self-centering dampers. The force-displacement relationship of VFHSCD is studied by theoretical and experimental methods first, and the self-centering and hysteretic energy-dissipating performances of the damper are then analyzed. The results show that the theoretical model of the force-displacement relationship of the damper agrees well with experimental results and presents typical flag-shaped self-centering characteristics and strong hysteretic energy dissipation performance. By using this theoretical force-displacement relationship, the effects of friction coefficient and inclination angle of the friction slopes, and the stiffness ratio and the pre-pressure ratio of the auxiliary restoring device to the transverse compression spring on the self-centering and damping performance of the VFHSCD are investigated. The results show that the VFHSCD can be optimally designed to obtain significant energy-dissipating capacity without the cost of weakening significantly its self-centering capacity.

Seismic performance of self-centering braced rocking frame with novel self-centering friction dampers characterized by low-secondary stiffness

Research has demonstrated that self-centering energy dissipation dampers (SCEDs) are effective devices for reducing the residual deformation of structures after a strong earthquake. However, the equivalent damping ratio of SCEDs is relatively lower than that of conventional dampers such as viscous dampers, BRBs, or friction dampers. According to displacement spectrums, the lower damping ratio could result in a lower natural period and higher equivalent stiffness of structures for a given displacement target, and thus the structures could attract more earthquake action to the structures. To alleviate the problem, a novel self-centering damper composed of elastic post-buckling plates and adjustable friction devices (PBSCFD) was proposed and used as the self-centering braces for a self-centering braced rocking frame (SBRF) structure for example. First, the theoretical force-displacement relationship of the PBSCFD was derived based on its configuration and work principle, and then a scaled PBSCFD was manufactured and tested to investigate its mechanical properties and verify the theoretical constitutive model. Subsequently, the SBRF structure with PBSCFDs was designed by the direct displacement-based seismic design method (DDBD), and its seismic performance was examined by elastic–plastic time-history analysis. Finally, the effects of the secondary stiffness ratio of the self-centering braces on seismic mitigation of the SBRF structure were investigated. The results show that PBSCFDs is characterized by classic self-centering behavior with low secondary stiffness, which can be designed to obtain significant control effects on the base/interstorey shear and interstorey drift ratio of the SBRF structure under rare and extremely rare earthquake compared to the conventional SCEDs with significant secondary stiffness.

Development and investigation of a self-centering cable brace with variable slip stiffness for braced frame structure

Extremely rarely occurring earthquake (EROE) level is currently not often considered in most national codes or standards, and the earthquake damage has shown that its consequences are serious. To control the seismic responses of the structures under the EROE level, a novel self-centering cable brace with variable slip stiffness (VSS-SCB) is proposed as the lateral force resisting component of braced frame structure. Firstly, the theoretical analysis of the damper in the VSS-SCB was carried out, it is found that the slope angle, friction coefficient, and compressive stiffness of the disc springs are the main parameters affecting the mechanical behavior of the damper. The combination of strong and weak stacks of disc springs can effectively provide a self-centering damper with adaptive stiffness. Then, pseudo-static tests were carried out on the design specimens of the damper. The test results show that the hysteretic curve of the self-centering cable brace with constant slip stiffness (CSS-SCB) presents a classical flag type, and the residual deformation can be ignored. When the disc spring stacks with different stiffness are combined in series, there are significant strengthened points for the loading and unloading stiffness of the brace. Finally, the displacement-based design method was applied to the design of the braced frame structures with the VSS-SCBs. The dynamic analysis shows that the braced frame structure with the CSS-SCBs has larger displacement response than that with the buckling-restrained braces (BRBs), and the hysteretic curves of the CSS-SCB and VSS-SCB show good self-centering capability. When the deformation of the CSS-SCB and VSS-SCB exceeds the strengthened point, the large strengthened stiffness of VSS-SCB can control the seismic response of the braced frame structure. The seismic fragility curves of the braced frame structures with the BRBs and with the VSS-SCBs are comparable, and are significantly smaller than that with the CSS-SCBs. However, since the BRB is prone to significant residual deformation, the braced frame structure with the VSS-SCBs has more advantages in improving the seismic resilience of the structure.

A novel self-centering friction damper with elastic post-buckling plates to retrofit bridge bents

The self-centering energy dissipation dampers (SCEDs) have been demonstrated in mitigating the residual deformation of structures under strong ground motions. However, existing researches show that the damping force demand of SCEDs is higher than conventional dampers such as viscous dampers, BRBs or friction dampers for same design displacement of self-centering retrofitted structures, which could lead to higher base shear and acceleration responses of structures. In order to alleviate the problem, a novel self-centering damper composed of elastic post-buckling plates and adjustable friction devices (PBSCFD) was proposed. Compared with conventional SCEDs, the proposed PBSCFD has low secondary stiffness and adjustable energy dissipation capacity, which is beneficial to control the additional internal force of members adjacent to the damper in self-centering retrofitted structures. Based on the configuration and working principle of the PBSCFD, the theoretical force-displacement relationship of the damper was derived. Subsequently, a scaled PBSCFD was manufactured and tested under quasi-static loading to investigate its mechanical properties and to verify the theoretical constitutive model. In order to demonstrate the seismic performance of PBSCFDs, the double-column bridge bent retrofitted with PBSCFDs was designed by direct displacement-based seismic design method (DDBD), and its seismic performance was examined by elastic-plastic time-history analysis. Finally, effects of secondary stiffness ratio of self-centering dampers on seismic mitigation of self-centering retrofitted bridge bent were investigated. The results show that PBSCFDs have certain advantages in controlling the base shear and acceleration of the retrofitted bridge bent compared to conventional SCEDs with significant secondary stiffness.

Review on self-centering damper for seismic resilient building structures

In recent years, major earthquakes in China, Chile, New Zealand and Japan caused many building structures severely damaged, which must be overhauled or rebuilt. Therefore, how to improve the seismic resilience of building structures has been widely concerned. The energy dissipation dampers are proposted to install in some parts of the structure to produce large damping and dissipate much seismic energy input. While, the disadvantage of these traditional dampers is that they cannot automatically restored to the original position after the earthquake, and the residual deformation may result in huge economic losses. In recent years, researchers proposed to combine self-centering devices with traditional dampers to obtain self-centering capacity in addition to energy dissipation capacity, and the self-centering dampers can effectively avoid post-earthquake damage of the structure. This paper first reviews the mechanical characteristics and development of traditional dampers, including metal yield dampers, friction dampers, viscoelastic dampers, viscous fluid dampers, etc. Then, the research of self-centering dampers is summarized according to the types of self-centering devices, including shape memory alloy (SMA) type, steel tendon and strand type, and mechanical spring type. Further, the experimental research and seismic design methods of structures with self-centering dampers are reviewed, as well as the classic engineering applications of different dampers. Finally, the future directions need to be concerned in the further research are mentioned, which is benefical to the future engineering popularization and applicaition of self-centering dampers.

Tests of double-stage SMA slip friction damper

This study presents a new type of self-centering damper, termed the double-stage shape memory alloy (SMA) slip friction damper, which mainly comprises of the grooved center and cap plates, stacked disc springs, and SMA bars. The double-stage behavior is realized by the serial connection of the stacked disc springs and the SMA bars, with the purposes of adjusting stiffness and damping for varied seismic hazard levels. The configuration and working mechanism are firstly presented, along with the analytical equations governing the force-displacement relationship. As the key components, the SMA bar, the friction mechanism, and the disc springs were tested separately. And then, the proof-of-concept tests of the reduced-scale damper were conducted. From the testing results, the damper exhibited a symmetric double-stage self-centering damping behavior. Some hysteretic parameters of interest were then quantified. Three-dimensional numerical models were established and were further used for parametric analysis. Both the analytical method and numerical model agree well with the experimental data.

Evaluating the Effectiveness of a New Self-Centering Damper on a Knee Braced Frame

The use of shape memory alloys (SMAs) has been receiving increasing attention among researchers due to their special properties. One of the most important features of SMA is the superelastic behavior which causes the alloy to be able to remove all the applied deformation. This study is intended to evaluate the application of superelastic Nitinol in knee braced steel frames (KBF) as a damper. To fulfill the objective of this research, an experimental KBF system has been developed in ABAQUS using the microscopic finite-element method (FEM). The proposed superelastic damper is placed between the knee element and beam-column connection. Five SMA dampers with different stiffness are located in the KBF system and subjected to static cyclic loading. The hysteresis diagram obtained from this cyclic loading indicates that the damper increases the system strength. The greater the stiffness of the SMA damper, the higher the strength is. Furthermore, the superelastic alloy reduces the permanent deformation and the dissipation energy capacity of the KBF system. Totally, the SMA-equipped KBF system indicates a little lower energy dissipation capacity compared to the KBF system. However, based on the hysteresis diagrams, the reduction of residual deformation in all models is significant compared to the little reduction in energy dissipation. Therefore, the proposed SMA damper is capable of reducing the permanent deformation of the KBF system and maintaining the energy dissipation capacity at almost the same level, which is essential for keeping the structure stable.

Seismic fragility assessment of a multi-span continuous I-girder bridge controlled by a self-centering damper

This study evaluated the seismic fragility and failure modes of a reinforced concrete bridge retrofitted with a self-centering damper. This damper was hybrid and included two parts. The first part was a butterfly-shaped metallic damper, which provided the dissipating energy, and the second part was prestressed polyurethanes, which played a self-centering role in the damper. In particular, an extensive time history analysis was performed on three scenarios. These scenarios include the behavior of 1) the bridge with restrainer (Bridge-R), 2) the bridge with the damper (Bridge-D), and 3) the bridge with restrainer and damper in the longitudinal and transverse directions, respectively (Bridge-RD). Notably, the seismic fragility curves of bridge components were generated first, and eventually, the bridge seismic fragility curve was generated before and after the bridge was retrofitted with the hybrid damper. The analysis showed that the damper could have a positive effect on the residual displacements of the deck and bearing and the shear key deformation in the bridges. However, the damper increased the rigidity between the deck and columns and led to extra demand in the columns, but the extra demand had no effect on the general behavior of the bridges.

Wavelet-Neural Network Based Robust Optimization of Self-Centering Viscous Damper for Steel MR Frame

ABSTRACT This study implements robust design optimization (RDO) of a self-centering viscous damper in the presence of seismic uncertainty. The RDO minimizes the effect of random input parameters on the output response, thus providing a robust solution. The optimal phenomenological parameters of the self-centering viscous damper are evaluated to ensure its robustness. The objective function of the RDO is cast as a sum of the mean and standard deviation of maximum floor acceleration and a constraint function of the inter-storey drift ratio of the floors. The mean component of the objective function minimizes the structural responses due to external loads, whereas the other component reduces the propagation of uncertainty from the input parameters. To reduce the computational cost of the RDO, a wavelet-based neural network is used as a surrogate model. The proposed optimization method is implemented in a 16-storey steel moment resisting frame with consideration of two ensembles of ground motions, i.e. far-field and near-field records, which are taken from FEMA P695 (ATC-63). To highlight the effectiveness of the proposed self-centering damper in mitigating maximum and residual drift ratios, two additional optimizations are undertaken using viscous and self-centering dampers. The numerical study shows that the neural network with a Gaussian wavelet function produces better accuracy compared to other wavelet functions. Also, the numerical analysis clearly elucidates the advantages of the proposed damper in reducing the residual drift of the floors over a viscous damper and a self-centering damper, which may lead to minimizing the post-earthquake economic losses.

A novel self-centering viscous damper for improving seismic resilience: Its development, experimentation, and system response

A novel self-centering viscous damper (SCVD) is developed to improve the seismic resilience of structures. The proposed damper offers high flexibility in load resistance, deformability, and excellent velocity-dependent energy dissipation characteristics. The detailed configuration, recommended fabrication process, basic working principle, and restoring force model are presented first, followed by comprehensive experimental studies on the damper specimen, where different initial preload, loading frequency, and loading amplitude are considered. The specimen shows typical flag-shaped hysteretic behavior, little strength degradation, and reliable energy dissipation, where a maximum equivalent viscous damping of 38.33% is achieved at high frequency, and the self-centering mechanism can be fully realized at the end of loading. Moreover, a system-level analysis is carried out to evaluate the effectiveness of such self-centering dampers as bracing elements in a building to control seismic demands. Here, a buckling-restrained braced frame and a conventional self-centering braced frame are considered for comparison purposes. Nonlinear dynamic analyses indicate that the proposed system exhibits an improved control of the peak deformation, residual deformation, and peak floor acceleration.

Hybrid self-centering rocking core system with fiction spring and viscous dampers for seismic resilience

This research presents a novel aseismic system, the hybrid self-centering rocking core (HSRC) system, for obtaining better seismic resilience in steel buildings. Two hybrid self-centering dampers are introduced in the HSRC system to control structural and nonstructural damage. A rocking core, i.e., a steel braced frame with pinned base is included in the HSRC system to facilitate uniform inter-story drift responses under earthquakes. The steel braces in the rocking core can also work as a reserve energy-absorbing mechanism against structural collapse subjected to extreme seismic events whose intensities are more significant than those of the maximum considered earthquakes in design codes. The desired nonlinear responses of the HSRC system were analyzed. Direct displacement-based design steps were developed for the HSRC system. Three-story and six-story HSRC systems were designed following the proposed design method. Nonlinear dynamic analysis results indicate that the designed HSRC systems can show desired nonlinear responses and achieve the expected performance objective under earthquakes. Moreover, seismic fragility analyses were also conducted based on the incremental dynamic analysis results to assess the performance in controlling structural and nonstructural damages of the HSRC system under earthquakes of different intensities. The results confirm that the proposed HSRC system has excellent capacity in resisting structural collapse, achieving reliable post-earthquake recoverability, and controlling structural and nonstructural damage under rare seismic events.

Evaluation of a Full-Scale Friction Spring-Based Self-Centering Damper Considering Cumulative Seismic Demand

Various self-centering (SC) structural systems have been developed and proven effective in ensuring structural resiliency over the last few decades. However, information on cumulative seismic demand for SC structural systems under seismic excitations, especially under mainshock–aftershock sequences and long-duration ground motions, is very limited. In this paper, the recommended design and fabrication processes for friction spring-based SC dampers are first presented. Accordingly, a 6-story braced frame equipped with the SC dampers is designed. A typical full-scale SC damper is subsequently manufactured and tested. To satisfy the codified requirement for practical application, two loading protocols are adopted to investigate the hysteretic and fatigue performance of the damper. The test results show that the damper has very stable flag-shaped hysteretic behavior and maintains excellent SC capability and moderate energy dissipation under multiple rounds of loading. In particular, the behavior of the damper is stable under 30 cycles of constant amplitude loading without visible degradation. After the experimental study, an accumulative seismic demand index is developed, followed by a system-level analysis performed on the considered structure under mainshock–aftershock and long duration earthquake excitations. It was found that the cumulative seismic capacity of the SC damper surpasses the corresponding cumulative seismic demand under the considered multiple earthquake excitations, and therefore no fatigue failure of the damper is expected.

Seismic collapse behavior of steel structures with a smart axial polyurethane friction damper

Shape memory alloys (SMA) are utilized in various engineering fields, owing to their unique properties. In this study, the collapse behavior of steel structures designed with a self-centering damper under seismic sequences was investigated. The proposed damper was made of SMA plates, friction devices, and polyurethane springs called axial polyurethane friction (APF) -SMA dampers to provide desirable damping capabilities and good self-centering behavior. Concentrically braced 14-story steel frames using four types of bracing systems (split X, chevron V, inverted chevron IV, and diagonal) were modeled in OpenSees with and without the APF-SMA damper to evaluate their seismic resistance performance. An incremental dynamic analysis (IDA) was performed for the frames, and the maximum inter-story drift IDA curves of the frames were developed and compared. The analysis results indicated that the APF-SMA damper limited the maximum inter-story drifts of the conventional steel frames and effectively reduced the residual inter-story drifts of the braced frames. Finally, the advantages of the proposed APF-SMA over the conventional braced frames were demonstrated through probabilistic analyses of the results based on the nonlinear response history analyses.

Manufacturing, testing and simulation of novel SMA-based variable friction dampers with enhanced deformability

This study presents a novel type of self-centering damper employing NiTi Shape Memory Alloy (SMA) bars combined with variable friction mechanism for tunable hysteretic behavior and enhanced deformability. The new damper, which is called SMA-based variable friction damper (SMA-VFD), aims to significantly amplify the maximum deformability and energy-dissipation capability compared with the existing self-centering devices with tensioning SMA members. The cyclic response, phase transformation behavior, and in-situ observation of the microstructure of individual SMA bars receiving different heat treatments were first investigated to promote an adequate understanding of the link between the microscopic structure and the macroscopic property of the large size SMA bars. This is followed by a detailed discussion of the SMA-VFD, where theoretical equations as well as three performance parameters, i.e., self-centering factor γ, displacement amplification factor ω, and energy-dissipation factor λ, were derived to predict the mechanical behavior of the damper. Proof-of-concept SMA-VFD specimens were manufactured, where different preloads and friction coefficients were considered which could affect the cyclic performance. A three-dimensional finite-element model was then developed to simulate the nonlinear responses of the test specimens. Both the analytical prediction and numerical simulation exhibited good agreements with the experimental results. Utilizing the validated numerical model, the influence of manufacturing tolerance on the initial stiffness of the proposed damper was particularly investigated to help explain some important findings from the present experimental study.

A novel lever-based-inerter-enhanced self-centering damping system to retrofit double-column bridge bent

Research has demonstrated that the self-centering dampers (SCDs) can mitigate the maximum and residual displacement of multi-column bridge bents under seismic excitation. Application of SCDs also increases the stiffness of bridge bents, which could intensify other seismic responses, such as base shear and acceleration. In order to alleviate the increments of these responses, a novel inerter-enhanced self-centering damping system (ISCDS) is proposed by adding a lever-based inerter (LBI) to the shape-memory alloy-based SCD in parallel. The displacement design spectrum, including the effect of the inerter, is developed based on an existing design acceleration spectrum. Two double-column bridge bents retrofitted with ISCDS and SCD are then designed by direct displacement-based design (DDBD) method, and their seismic performance is examined and compared by elastic-plastic time history analysis. The results show the bridge bent retrofitted with ISCDS has obvious advantages in terms of reducing the use of self-centering material, maximum acceleration and maximum base shear compared to bridge bent with SCD under the premise of the similar control performance of maximum and residual displacement. Finally, the effects of the inertance-mass-ratio and amplification factor on the seismic performances of the retrofitted bridge are investigated, and the reasonable values of the two parameters are suggested.