High Damping Rubber Research Articles

Experimental verification of the compressive stiffness of high-damping rubber bearings (HDRB) according to STN EN 1337-3 and their effectiveness in seismic isolation for cable-stayed bridges

Experimental verification of the compressive stiffness of high-damping rubber bearings (HDRB) according to STN EN 1337-3 and their effectiveness in seismic isolation for cable-stayed bridges

Multi-level stiffness property and isolating-based design of high damping rubber bearings

This study presents the development and analysis of high damping rubber bearings (HDRBs) with enhanced stiffness properties to improve seismic isolation performance. The proposed HDRBs exhibit displacement-dependent nonlinear stiffness and significant damping effects, especially under large deformations caused by various seismic events. A deformation history integral model, calibrated with experimental data, is employed to accurately simulate the mechanical behavior and stiffness-damping characteristics of the HDRBs. The numerical simulations are validated through experimental tests, providing a solid basis for parameter design and performance assessment. The results show that the equivalent stiffness coefficient of the HDRBs increases with deformation amplitude, effectively limiting extreme deformations. Parametric analyses and case studies across a wide range of earthquake scenarios demonstrate that the enhanced stiffness and high damping effects of HDRBs significantly improve seismic isolation efficiency while controlling isolation layer displacement. The performance-based design methodology developed in this research effectively limits bearing deformation, thereby preventing potential superstructure failures. Moreover, the adaptive characteristics of the HDRBs allow for the adjustment of deformation levels according to seismic intensity, ensuring the structural safety of buildings under varying earthquake conditions.

Study on a Pseudo-Elastic Model for High-Damping Rubber.

With advancements in seismic isolation and damping technology, high-damping rubber (HDR) bearings are now widely used. However, significant gaps remain in HDR-analysis model research, with few studies integrating multiple factors, the Mullins effect, and stiffness hardening for more accurate practical predictions. This study classifies the effective behavior of HDR and examines the stress-strain relationships of different behavioral types using more appropriate equations. Mathematical models were established based on pseudo-elasticity theory, which is an extension of continuum mechanics. Subsequently, parameter functions were developed through parameter determination tests and regression analysis, leading to the completion of the pseudo-elastic model for HDR. Finally, the model's effectiveness was validated through validation tests. This study finds that behavior classification effectively examines phenomenological-based HDR stress-strain relationships, as distinct behavioral patterns are not adequately captured by a single approach. Incorporating tests to functionalize material parameters complements theoretical models. Additionally, accurately explaining HDR behavior requires considering the Mullins effect and stiffness hardening, influenced by the coupled effects of temperature, strain amplitude, and compressive stress. Consequently, this HDR pseudo-elastic model offers a comprehensive explanation of HDR behavior, including the Mullins effect and stiffness hardening, under various influencing factors based on clear mechanical principles and explicit computational procedures.

Experimental study on the cyclic performance of innovative self-centering three-dimensional isolation bearing

To improve vertical seismic isolation and seismic resilience in isolation bearings, this paper introduces an innovative three-dimensional isolation bearing combining a disc-spring system (DSS), a high-damping rubber bearing (HDR), and a horizontal spring system (HSS). The DSS is designed with low vertical stiffness to enhance vertical isolation, while the HSS provides self-centering force to improve the seismic resilience of the HDR. This study first presents a comprehensive theoretical analysis of the horizontal and vertical stiffness composition. The vertical performance of this three-dimensional isolation bearing is attributed to the DSS, while the HSS and HDR jointly contribute to its horizontal performance. Seven specimens were designed and subjected to shear-compression cyclic tests to assess the horizontal and vertical cyclic performance. Experimental parameters included loading amplitude, loading frequency, vertical pre-load, and DSS combinations for vertical tests, and axial compression force, loading frequency, shear strain, and HSS function in horizontal tests. The cyclic performance parameters for the three-dimensional isolation bearing, including equivalent damping ratio, equivalent stiffness, and energy dissipation, was evaluated. In general, the proposed three-dimensional isolation bearing exhibits stable cyclic performance and advantageous seismic resilience, warranting its promotion to practical engineering applications.

Local resonance metamaterial-based integrated design for suppressing longitudinal and transverse waves in fluid-conveying pipes

To solve the problem of low broadband multi-directional vibration control of fluid-conveying pipes, a novel metamaterial periodic structure with multi-directional wide bandgaps is proposed. First, an integrated design method is proposed for the longitudinal and transverse wave control of fluid-conveying pipes, and a novel periodic structure unit model is constructed for vibration reduction. Based on the bandgap vibration reduction mechanism of the acoustic metamaterial periodic structure, the material parameters, structural parameters, and the arrangement interval of the periodic structure unit are optimized. The finite element method (FEM) is used to predict the vibration transmission characteristics of the fluid-conveying pipe installed with the vibration reduction periodic structure. Then, the wave/spectrum element method (WSEM) and experimental test are used to verify the calculated results above. Lastly, the vibration attenuation characteristics of the structure under different conditions, such as rubber material parameters, mass ring material, and fluid-structure coupling effect, are analyzed. The results show that the structure can produce a complete bandgap of 46 Hz–75 Hz in the low-frequency band below 100 Hz, which can effectively suppress the low broadband vibration of the fluid-conveying pipe. In addition, a high damping rubber material is used in the design of the periodic structure unit, which realizes the effective suppression of each formant peak of the pipe, and improves the vibration reduction effect of the fluid-conveying pipe. Meanwhile, the structure has the effect of suppressing both bending vibration and longitudinal vibration, and effectively inhibits the transmission of transverse waves and longitudinal waves in the pipe. The research results provide a reference for the application of acoustic metamaterials in the multi-directional vibration control of fluid-conveying pipes.

Analytical Solution for Dynamic Response of a Reinforced Concrete Beam with Viscoelastic Bearings Subjected to Moving Loads.

To provide a theoretical basis for eliminating resonance and optimizing the design of viscoelastically supported bridges, this paper investigates the analytical solutions of train-induced vibrations in railway bridges with low-stiffness and high-damping rubber bearings. First, the shape function of the viscoelastic bearing reinforced concrete (RC) beam is derived for the dynamic response of the viscoelastic bearing RC beam subjected to a single moving load. Furthermore, based on the simplified shape function, the dynamic response of the viscoelastic bearing RC beam under equidistant moving loads is studied. The results show that the stiffness and damping effect on the dynamic response of the supports cannot be neglected. The support stiffness might adversely increase the dynamic response. Further, due to the effect of support damping, the free vibration response of RC beams in resonance may be significantly suppressed. Finally, when the moving loads leave the bridge, the displacement amplitude of the viscoelastic support beam in free vibration is significantly larger than that of the rigid support beam.

Seismic Vulnerability Analysis of Concrete-Filled Steel Tube Tied Arch Bridges Using Symmetrically Arranged High-Damping Rubber Bearings

Seismic Vulnerability Analysis of Concrete-Filled Steel Tube Tied Arch Bridges Using Symmetrically Arranged High-Damping Rubber Bearings

Glass-Aluminium Partition Walls with High-Damping Rubber Devices: Seismic Design and Numerical Analyses

Glass-Aluminium Partition Walls with High-Damping Rubber Devices: Seismic Design and Numerical Analyses

Damping ratio of stay cable attached with viscous damper and high-damping rubber damper

Damping ratio of stay cable attached with viscous damper and high-damping rubber damper

Finite element analysis of a rubber bearing base isolator under vertical and horizontal loads using a nonlinear hyper-viscoelastic material model

This research is devoted to developing a finite element model using Abaqus code for the computer simulation of an in-house developed and manufactured rubber bearing subjected to static vertical and cyclic horizontal loads. A high-damping rubber compound was designed. The material behavior of the rubber was assumed to be described by the hyper-viscoelastic model. Both linear (Prony series) and nonlinear (strain hardening power law) viscoelastic relationships were used in conjunction with the Ogden-Roxburgh equation to take the addition of the stress softening phenomenon or Mullins effect into consideration. The parameters of the material model were determined using MCalibration code in which an optimization technique was used, and data obtained in experiments carried out on test specimens were fitted into the selected model. The results of the simulations were compared with their corresponding experimental data carried out on the rubber bearing. The force-displacement behavior, stress and strain fields, and computed energy were presented and discussed. It is shown that the nonlinear viscoelastic model accompanied by the Mullins effect gives the best results. Moreover, the model could accurately predict the energy variations during the earthquake loading.

Visco-Hyperelastic Constitutive Modeling for High-Damping Rubber Materials During Combined Quasi-Static Compression–Cyclic Shear Deformation Process

High-damping rubber materials utilized in high-damping rubber isolation bearings are frequently subjected to multiple deformations during the occurrence of earthquakes. Typically, large combined compression–shear deformations of the material could potentially cause compressive shear damage to rubber bearings. During this process, visco-hyperelastic properties of rubber materials will greatly change, which would significantly impact the seismic performance of rubber bearings. Thus, to give out a deep insight into their variations, it is necessary and urgent to develop a high-performance numerical method to investigate this process. This paper proposed a visco-hyperelastic constitutive modeling approach for high-damping rubber materials based on the experimental assessment of combined quasi-static compression–cyclic shear deformation process. Within the thermodynamic framework, the Clausius–Duhem inequality associated with the intrinsic dissipation of the material was firstly derived in accordance with the Lagrangian formulism. Then, stress–strain relations were obtained upon considering the occurrence of entropy production due to viscous dissipation. In the model, Stumpf–Marczak strain energy density function, which satisfies the Baker–Ericksen (B–E) inequality, was harnessed to describe the hyperelasticity of the material. By introducing higher orders of strain and strain rates and taking their couplings into account, a generalized viscous dissipation potential was proposed to capture nonlinear strain and strain rate-sensitivity effects of the material. To identify constitutive parameters, the deformation gradient was particularized for the combined quasi-static compression–cyclic shear deformation process. And, an inverse identification procedure was carried out at different levels of compression stress. The prediction results revealed that the proposed model exhibits remarkable prediction ability and adaptivity for different rubber materials during this process. Several new insights were highlighted on the variations of visco-hyperelastic characteristics of high-damping rubber materials with respect to the compression stress. The accuracy of the model was further validated by design parameters including initial shear modulus, secant shear modulus and equivalent viscous damping factor. This work could provide a fundamental guideline for the optimization and reliability analysis of high-damping rubber isolation bearings used in the field of seismic engineering.

Testing novel hybrid inter-module joints for steel modular buildings under cyclic load

To bridge the gap between the unrealised disassembly and reuse potential of volumetric modular buildings and the lack for seismic resilience, a hybrid inter-module connection employing a high-damping rubber bearing was proposed to reduce the inelastic deformation in the members of the volumetric module. The cyclic behaviour of the proposed connection was previously investigated at connection level through validated proof-of-concept FEA, reflecting promising damping and re-centring capabilities. In this study, six in-plane cyclic loading tests on inter-module joints with the novel, hybrid inter-module connection were carried out to investigate the connection’s influence on the cyclic behaviour of steel modular buildings under lateral load at joint level. The tests focused on the contribution of the laminated elastomeric bearing to the joint’s lateral behaviour and the effect of different bolting assemblies on the working mechanism of the hybrid connection system. The standard FEMA/SAC loading sequence was employed on single-span, meso-scale joint prototypes with axial and in-plane lateral loading applied to the top post. The results showed that the hybrid IMJs exhibited nonlinear, multi-stage hysteretic responses, governed by the bending resistance of the bolting assembly and the stiffness of the intra-module connection. The aseismic performance of the joints was characterised by residual drifts below the permissible limit of 0.5 % up to 2 % drift ratio and high equivalent viscous damping during the low-amplitude cycles. Overall, the tests demonstrated the feasibility of the proposed connection with respect to the mitigation of damage in the structural elements of the volumetric modules after an earthquake, as proved by the low inelastic deformation recorded up to 4 % drift ratios.

An innovative energy-dissipation angle bracket for CLT structures: Experimental tests and numerical analysis

The connection system controls the behavior of the Cross-laminated timber (CLT) structures under horizontal loads. This paper introduced an innovative energy-dissipation angle bracket for CLT structures, which takes advantage of the soft-steel bracket and high-damping rubber to provide superior ductility and energy-dissipating capacity. Experimental tests under monotonic and reversed cyclic loading were performed to investigate the failure mechanism and mechanical properties of this energy-dissipation connector. After validating the detailed finite element models based on the test results, numerical parametric analysis was conducted to evaluate the influence of several parameters. The results show that the energy-dissipation angle bracket connector mainly exhibits three failure modes, including the rupture of dissipative ribs, local bearing failure of the base, and the debonding of the internal rubber. The ribs’ rupture is the dominant failure mode, especially under cyclic loading, after which the connector can still work integrally because of the rubber that is tightly bonded to the steel skeleton. All the tested connectors show high ductility and great energy-dissipating capacity, as indicated by the ductility larger than 9.5 and the equivalent viscous damping ratio within 9 %− 26 %. According to the numerical parametric analysis, the load-carrying capacity of the energy-dissipation angle bracket is positively correlated with the steel skeleton’s thickness and ultimate strength, and the adoption of the washer, while the rubber’s height has little impact on the load-carrying capacity. The outcomes of this study provide valuable references for subsequent improvement and potential applications of the innovative angle bracket for CLT structures.

An Experimental Study of High-Damping Rubber Bearings (HDRB) and Their Implications for the Seismic Performance of Cable-Stayed Bridges

This article investigates the efficiency of high damping rubber bearings (HDRB), which are made of special rubber with excellent damping attributes and layers of steel. HDRB isolators have excellent flexibility, vibration reduction ability, and high restoring ability for controlling the seismic response of long-span cable-stayed bridge systems under near-fault ground motions. The seismic isolation of cable-stayed bridges is achieved using high-damping rubber bearings (HDRB). High-damping rubber bearings have excellent seismic effects during earthquakes. The elastic stiffness of the bearing depends on the degree of deformation. When the deformation is small, the stiffness will be large. Therefore, compressive stiffness is one of the key parameters in the design of seismic isolation bearings for cable-stayed bridges. For this reason, predicting the behavior of high-damping rubber bearings under compressive loads is highly important for their design. Therefore, the experimental verification of high-damping rubber bearings (HDRB) for compressive loading was tested according to the standard assumptions in STN EN 1337-3. Firstly, periodic vertical compression tests are performed, and the high damping rubber (HDRB) capabilities and energy dissipation are analysed, taking into account the effect of vertical compression and loading frequency. Secondly, a corrected calculation of the vertical stiffness for high-damping rubber bearings is proposed based on experimental data to provide a more accurate and realistic tool for measuring the vertical mechanical properties of rubber bearings. The test results prove that HDRB has the most advanced performance. For the fatigue property, the hysteresis curves of the HDRB plump both vertically, which provides a good energy dissipation effect. DOI: https://doi.org/10.52783/pst.431

Damping effects of a stay cable attached with a viscous damper and a high damping rubber damper considering cable bending stiffness and damper support flexibility

To mitigate cable oscillations in cable-stayed bridges, a common approach involves using a strategically positioned viscous damper near the cable’s anchorage and bridge deck. However, for longer cables, this method may be insufficient due to installation constraints. In such cases, supplementing the damping system with a high-damping rubber (HDR) damper near the cable’s anchorage point on the bridge tower becomes imperative to enhance the cable’s damping ratio. Conventional designs often overlook crucial factors like viscous damper support stiffness and stay cable bending stiffness when integrating dampers into cable-stayed structures. This study presents findings on achieving an effective damping ratio in stay cables by using both a viscous damper and an HDR damper, considering the influence of viscous damper support stiffness and stay cable bending stiffness. The results indicate that the combined deployment of these dampers achieves a damping efficiency approximately equivalent to the sum of their individual effects. Importantly, decreased viscous damper support stiffness significantly affects the damping effectiveness, leading to a rapid decline in the stay cable’s damping ratio. While stay cable bending stiffness also influences the damping ratio, its impact is relatively less pronounced than that of viscous damper support stiffness. The study outcomes enable a more accurate prediction of the achievable damping ratio for a stay cable with additional components, considering both damper support stiffness and stay cable bending stiffness. Furthermore, the study explores parameters of both the viscous damper and HDR damper, such as the viscous coefficient, loss coefficient, HDR damper stiffness, and damper placement, evaluating their influence on the first damping ratio of the stay cable. The survey results provide valuable insights for determining optimal parameters for both dampers, maximizing the damping efficiency of cable-stayed bridges.

Cross-ties with linear hysteretic damping for cable vibration mitigation: Theoretical analysis and full-scale experiment

This study investigates cross-ties with linear hysteretic damping (HDCs) for vibration mitigation of stay cables through theoretical analysis and full-scale experiments. The formed cable networks are modeled by considering cables as taut strings and the HDCs as mass-less elements of complex stiffness. Frequency equation of the system is formulated analytically and is solved numerically. Then, the influence of HDCs on system dynamics is discussed for typical cable networks and considering HDCs realized by a rigid tie in series with high damping rubber. The results indicate that the HDCs can realize high damping for multiple modes because of the frequency independency of hysteretic damping and no restriction on the installation location. Increasing the loss factor of the cross-tie is significant for improving system damping, but less effective for system frequency modification. Extending HDCs to the ground and using multiple HDCs are effective in further enhancing multi-mode frequency and damping of the system. Furthermore, full-scale experimental validations and investigations are conducted based on three cables of approximately 40 m. Experimental results have validated the effectiveness of HDC in enhancing system damping. This study demonstrates that the easily implementable HDCs have excellent performance in vibration mitigation of multi-mode cable vibrations.

Experimental study and numerical model of a new passive adaptive isolation bearing

This study presents a novel assembled passive adaptive isolation bearing (PAIB) for structures against various seismic design levels, which offering variable stiffness functions change with the displacement, vertical stress and rate. The operational mechanism of the bearing is initially described, followed by experiments conducted on 6 specimens with NR (Natural rubber) drum dampers and 10 specimens with HDR (High damping rubber) drum dampers. The test results demonstrate a notable hardening segment in the horizontal shear force of HDR drum dampers compared to NR drum dampers when lateral displacement exceeds 200% total rubber thickness. Furthermore, the friction characteristics of sliding polyurethane elastomer bearing with different friction surfaces and the lateral mechanical properties of the whole device under different working conditions are examined. A numerical model, considering strong nonlinear reinforcement and frictional nonlinearity, is proposed based on the OpenSees platform, and its effectiveness is verified thorough experimental investigation. Additionally, parameter analyses are carried out to assess the contribution of each component of the new bearing to the lateral stiffness adaptive performance and the proportion of energy dissipation. The findings reveal that the hysteretic behavior of PAIB equipped with HDR drum dampers exhibits significant correlations between velocity, vertical pressure, and displacement. This highlights its excellent adaptability in both design and earthquake beyond the designed level, particularly when the frictional energy consumption remains relatively low.

Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings

Abstract This study evaluates seismic mitigation methods, including high damping rubber bearing, lead rubber bearing, double sliding pendulum (DSP), and tuned mass damper (TMD), considering earthquake intensity, building height, and isolation level. Moreover, the study delves into a novel approach that incorporates multi-level isolation and multi-level TMD. Reinforced concrete buildings, ranging in height from 4 to 40 storeys, were nalysed and nalysed using SAP2000 under the seismic influence of the Badra, El Centro, and Northridge earthquakes. The study reveals a significant rise in the fundamental period (T) with base isolation systems, reaching 378% of the fixed base value for a six-storey building. Building height directly affects T values, with simplified equations introduced for calculation. DSP proves 5% more efficient in reducing base shear (BS), while TMD is effective in weaker earthquakes for minimizing lateral displacement. Base isolators outperform mid-level isolation and TMD at the top storey. Combining base isolators with TMD at the top storey is deemed impractical and uneconomical. The study recommends multilevel isolation or multilevel TMD for enhanced seismic isolation efficiency, with four-level isolation achieving an 80% reduction in BS for 12-storey buildings. In addition, four-level TMD outperforms TMD at the top storey with a 44.5% reduction in BS, surpassing the 26.6% reduction achieved with TMD at the top storey only.

Seismic performance analysis of building structures using high damping rubber bearings

Seismic performance analysis of building structures using high damping rubber bearings

Developing a New Constitutive Model of High Damping Rubber by Combining GRU and Attention Mechanism.

High damping rubber (HDR) bearings are extensively used in seismic design for bridges due to their remarkable energy dissipation capabilities, which is critical during earthquakes. A thorough assessment of crucial factors such as temperature, rate, experienced maximum amplitude, and the Mullins effect of HDR on the mechanics-based constitutive model of HDR is lacking. To address this issue, we propose a deep learning approach that integrates the Gate Recurrent Unit (GRU) and attention mechanism to identify time series characteristics from compression-shear test data of HDR specimens. It is shown that the combination of GRU and attention mechanism enables accurate prediction of the mechanical behavior of HDR specimens. Compared to the sole use of GRU, this suggested method significantly reduces model complexity and computation time while maintaining good prediction performance. Therefore, it offers a new approach to constructing the HDR constitutive model. Finally, the HDR constitutive model was used to analyze the impact of experienced maximum amplitudes and cycles on following processes. It was observed that maximum amplitudes directly influence the stress-strain relationship of HDR during subsequent processes. Consequently, a solid foundation is laid for evaluating the responses of HDR bearings under earthquakes.