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1
Jacob, Kiran, Aditya Suryadi Tan, Thomas Sattel, and Manfred Kohl. "Enhancement of Shock Absorption Using Hybrid SMA-MRF Damper by Complementary Operation." Actuators 11, no. 10 (September 30, 2022): 280. http://dx.doi.org/10.3390/act11100280.
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A hybrid damper concept is presented here using a combination of a Magnetorheological (MR) Fluid (MRF) and Shape Memory Alloy (SMA)-based energy dissipation. A demonstration is performed utilizing the shear operating mode of the MRF and the one-way effect of the SMA. The damping performance of different MRF–SMA configurations is investigated and the corresponding energy consumption is evaluated. We demonstrate that the operation of MRF and SMA dampers complement each other, compensating for each other’s weaknesses. In particular, the slow response from the MR damper is compensated by passive SMA damping using the pseudoplastic effect of martensite reorientation, which can dissipate a significant amount of shock energy at the beginning of the shock occurrence. The MR damper compensates for the incapability of the SMA to dampen subsequent vibrations as long as the magnetic field is applied. The presented hybrid SMA–MR damper demonstrates superior performance compared to individual dampers, allowing for up to five-fold reduction in energy consumption of the MR damper alone and thereby opening up the possibility of reducing the construction volume of the MR damper.
2
Wang, Zhi Hao. "Experimental Study on Multi-Mode Vibration Control of a Stay Cable with a Passive Magnetorheological Damper." Applied Mechanics and Materials 361-363 (August 2013): 1402–5. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.1402.
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Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. For super-long cables, passive linear damper cannot provide sufficient damping since it can be only optimum for a given mode of cable, while a long cable may vibrate with several modes. This paper focuses on multi-mode vibration control of stay cables with passive magnetorheological (MR) dampers. Firstly, a 21.6m-long model cable was designed and established in the laboratory.Then, control performance of the cable with a passive MR damper was tested. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the MR damper. It is further demonstrated that optimal tuned passively operated MR damper can outperform the passive viscous damper.
3
Qian, Hui, Hongnan Li, Gangbing Song, and Wei Guo. "Recentering Shape Memory Alloy Passive Damper for Structural Vibration Control." Mathematical Problems in Engineering 2013 (2013): 1–13. http://dx.doi.org/10.1155/2013/963530.
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This paper presents a preliminary study on the evaluation of an innovative energy dissipation system with shape memory alloys (SMAs) for structural seismic protection. A recentering shape memory alloy damper (RSMAD), in which superelastic nitinol wires are utilized as energy dissipation components, is proposed. Improved constitutive equations based on Graesser and Cozzarelli model are proposed for superelastic nitinol wires used in the damper. Cyclic tensile-compressive tests on the damper with various prestrain under different loading frequencies and displacement amplitudes were conducted. The results show that the hysteretic behaviors of the damper can be modified to best fit the needs for passive structural control applications by adjusting the pretension of the nitinol wires, and the damper performance is not sensitive to frequencies greater than 0.5 Hz. To assess the effectiveness of the dampers for structural seismic protection, nonlinear time history analysis on a ten-story steel frame with and without the dampers subjected to representative earthquake ground motions was performed. The simulation results indicate that superelastic SMA dampers are effective in mitigating the structural response of building structures subjected to strong earthquakes.
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Yang, Yi Qing, and Wei Dai. "Optimization of the Two-DOF Passive Damper for the Machining Vibration Control Based on the SDM." Materials Science Forum 770 (October 2013): 253–56. http://dx.doi.org/10.4028/www.scientific.net/msf.770.253.
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Two-DOF (Degree-of-Freedom) passive damper is found to be able to attain better performance than the Single-DOF damper in the machining vibration control. However, the optimization is much more complicated as there are more design variables. A new approach of optimizing the Two-DOF passive damper is proposed based on the Structural Dynamical Modification (SDM) method. The physical model of Two-DOF damper damping single mode is presented, and the Frequency Response Function (FRF) of the primary structure are formulated. Numerical simulation is carried out and the optimal geometrical parameters are obtained with an objective ofHnorm. It is found that the Two-DOF passive damper can achieve the best vibration suppression effect than the SDOF damper, two separate SDOF dampers and uniform-density bar while the mass ratio is the same.
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Baheti, Akshay Satishkumar, and Vasant Annasaheb Matsagar. "Wind and Seismic Response Control of Dynamically Similar Adjacent Buildings Connected Using Magneto-Rheological Dampers." Infrastructures 7, no. 12 (December 7, 2022): 167. http://dx.doi.org/10.3390/infrastructures7120167.
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Wind and/or earthquake-imposed loadings on two dynamically similar adjacent buildings cause vigorous shaking that can be mitigated using energy dissipating devices. Here, the vibration response control in such adjacent structures interconnected with semi-active magneto-rheological (MR) dampers is studied, which could also be used as a retrofitting measure in existing structures apart from employing them in new constructions. The semi-active nature of the MR damper is modeled using the popular Lyapunov control algorithm owing to its least computational efforts among the other considered control algorithms. The semi-active performance of the MR damper is compared with its two passive states, e.g., passive-off and passive-on, in which voltage applied to the damper is kept constant throughout the occurrence of a hazard, to establish its effectiveness even during the probable electric power failure during the wind or seismic hazards. The performance of the MR damper, in terms of structural response reduction, is compared with other popular energy dissipating devices, such as viscous and friction dampers. Four damper arrangements have been considered to arrive at the most effective configuration for interconnecting the two adjoining structures. Structural responses are recorded in terms of storey displacement, storey acceleration, and storey shear forces. Coupling the two adjacent dynamically similar buildings results in over a 50% reduction in the structural vibration against both wind and earthquake hazards, and this is achieved by not necessarily connecting all the floors of the structures with dampers. The comparative analysis indicates that the semi-active MR damper is more effective for response control than the other passive dampers.
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Zhang, Peng, Dabin Zhu, Huli Dong, Zeng Wang, Jiaao Wang, and Xiying Chen. "Considering lateral bending and torsion coupling in shimmy analysis of the nose landing gear." Journal of Physics: Conference Series 2658, no. 1 (December 1, 2023): 012053. http://dx.doi.org/10.1088/1742-6596/2658/1/012053.
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Abstract This paper focuses on the shimmy damper performance of nose landing gear and aims to establish and amend a five-dimensional dynamic model of nose landing gear. The study compares the shimmy damper performance of nose landing gear whether considering lateral bending and torsional vibrations coupling and concludes that the amended model provides greater accuracy. In addition, the research compares the shimmy performance of passive and active shimmy dampers, finding that the active shimmy damper significantly outperforms the passive one in terms of efficiency. The amended model is also shown to improve the shimmy damper performance of active shimmy damper.
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Ahmad, Aabas. "Analysis of Load Reduction of Floating Wind Turbines Using Passive Tuned Mass Dampers." International Journal for Research in Applied Science and Engineering Technology 9, no. 9 (September 30, 2021): 1340–45. http://dx.doi.org/10.22214/ijraset.2021.38179.
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Abstract: An efficient method for restraining the large vibration displacements and loads of offshore floating wind turbines under harsh marine environment is proposed by putting tuned mass dampers in the cabin. A dynamics model for a barge-type offshore floating wind turbine with a fore–aft tuned mass damper is established based on Lagrange’s equations; the nonlinear least squares Leven berg–Marquardt algorithm is employed to identify the parameters of the wind turbine; different parameter optimization methods are adopted to optimize tuned mass damper parameters by considering the standard deviation of the tower top longitudinal displacement as the objective function. Aiming at five typical combined wind and wave load cases under normal running state of the wind turbine, the dynamic responses of the wind turbine with/without tuned mass damper are simulated and the suppression effect of the tuned mass damper is investigated over the wide range of load cases. The results show that when the wind turbine vibrates in the state of damped free vibration, the standard deviation of the tower top longitudinal displacement is decreased approximately 60% in 100 s by the optimized tuned mass damper with the optimum tuned mass damper mass ratio 1.8%. The standard deviation suppression rates of the longitudinal displacements and loads in the tower and blades increase with the tuned mass damper mass ratio when the wind turbine vibrates under the combined wind and wave load cases. When the mass ratio changes from 0.5% to 2%, the maximum suppression rates vary from 20% to 50% correspondingly, which effectively reduce vibration responses of the offshore floating wind turbine. The results of this article preliminarily verify the feasibilities of using a tuned mass damper for restraining vibration of the barge-type offshore floating wind turbine
8
Luong, Quoc Viet, Dae-Sung Jang, and Jai-Hyuk Hwang. "Intelligent Control Based on a Neural Network for Aircraft Landing Gear with a Magnetorheological Damper in Different Landing Scenarios." Applied Sciences 10, no. 17 (August 28, 2020): 5962. http://dx.doi.org/10.3390/app10175962.
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A typical oleo-pneumatic shock-absorbing strut (classic traditional passive damper) in aircraft landing gear has a metering pin extending through the orifice, which can vary the orifice area with the compression and extension of the damper strut. Because the metering pin is designed in a single landing condition, the traditional passive damper cannot adjust its damping force in multiple landing conditions. Magnetorheological (MR) dampers have been receiving significant attention as an alternative to traditional passive dampers. An MR damper, which is a typical semi-active suspension system, can control the damping force created by MR fluid under the magnetic field. Thus, it can be controlled by electric current. This paper adopts a neural network controller trained by two different methods, which are genetic algorithm and policy gradient estimation, for aircraft landing gear with an MR damper that considers different landing scenarios. The controller learns from a large number of trials, and accordingly, the main advantage is that it runs autonomously without requiring system knowledge. Moreover, comparative numerical simulations are executed with a passive damper and adaptive hybrid controller under various aircraft masses and sink speeds for verifying the effectiveness of the proposed controller. The main simulation results show that the proposed controller exhibits comparable performance to the adaptive hybrid controller without any needs for the online estimation of landing conditions.
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Ferreyra, María Victoria, Julián M. Gómez-Paccapelo, Ramiro Suarez, and Luis A. Pugnaloni. "Avoiding chaos in granular dampers." EPJ Web of Conferences 249 (2021): 15003. http://dx.doi.org/10.1051/epjconf/202124915003.
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Granular dampers are passive devices used to attenuate mechanical vibrations. The most common configuration consists in an enclosure, partiallyfilled with particles, attached to the vibrating structure that needs to be damped. The energy is dissipated due to inelastic collisions and friction between the grains and between the grains and the inner walls of the container as the structure vibrates. As a result of the collisions, the mechanical response of the system often results in chaotic motion even if the driving is harmonic. Despite the vibration attenuation achieved, this chaotic response may render the granular damper unsuitable for a range of applications. In this work, we showcase two simple modifications of the enclosure design that are able to mitigate the chaotic response of the granular damper. To this end we use Discrete Element Method simulations of: (a) a granular damper with a conical base, and (b) a granular damper with obstaclesfixed inside the enclosure. We compare results against a standardflat-base enclosure damper. The basic mechanical response of the dampers is characterized by measuring the apparent mass and the loss factor. The suppression of the chaotic response is assessed qualitatively via the phase space diagram.
10
Tan, Aditya Suryadi, Thomas Sattel, and Richard Subianto. "A Novel Design Concept of a Magnetorheological Fluid-Based Damper Utilizing the Porous Medium for Implementation in Small-Scale Applications." Fluids 8, no. 7 (July 7, 2023): 203. http://dx.doi.org/10.3390/fluids8070203.
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Magnetorheological (MR) dampers have a virtue over conventional dampers, where their damping properties can be adjusted using a magnetic field. However, MR dampers have been barely implemented in small vibratory systems, in which the modal mass and stiffness are relatively small. This is due to two major reasons, namely its high parasitic damping force and big moving mass. When such an MR damper is installed in a small vibratory system, the system‘s default damping ratio is increased and therefore its dynamic is reduced. Here, a new concept of an MR damper utilizing the porous medium and shear operating mode together with an external non-moving electromagnet is proposed. This combination results in an MR damper with a low parasitic damping force and a small moving mass. For comparison purposes, a benchmark MR damper with comparable geometry is constructed. The proposed MR damper possesses a passive friction force that is 8× smaller and OFF-state passive viscous damping that is 10–20× smaller than the benchmark MR damper. An investigation of the proposed MR damper performance in a test vibratory system shows almost no reduction of the system dynamic. Therefore, this proposed MR damper configuration can be suitable for applications in small vibratory systems.
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Kim, Young Moon, Ki Pyo You, Jang Youl You, Sun Young Paek, and Byung Hee Nam. "LQG Control of Along-Wind Responses of Tall Building Using Composite Tuned Mass Dampers." Key Engineering Materials 723 (December 2016): 753–59. http://dx.doi.org/10.4028/www.scientific.net/kem.723.753.
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A composite tuned mass damper(CTMD) is a vibration control device consisting of an active-passive tuned mass dampers supported on the primary vibrating structure. The performance of CTMD in mitigating wind-induced vibration of tall building is investigated. Optimum parameters of a passive tuned mass damper(PTMD)for minimizing the variance response of the damped primary structure under random loads, with different mass ratio of an active tuned mass damper(ATMD) to a PTMD have been used for the optimum parameters of CTMD. The active control force generated by ATMD actuator was estimated by using linear quadratic Gaussian(LQG) controller, and the fluctuating along-wind load, treated as a stationary random process ,was simulated numerically using the along-wind load spectrum proposed by Solari .Comparing the along-wind rms response of tall building without a CTMD, the CTMD is effective in reducing the response to 40%~45% of the response without the CTMD. Therefore, the CTMD system was effective in reducing wind-induced vibration of tall building.
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Li, Ji-long, Ya-nan Tang, and Xuan-ming Liu. "Research on Dissipation and Fatigue Capacity of Nonstiffener Shear Panel Dampers." Advances in Civil Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/191359.
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Passive energy dissipation control system can effectively control structure response under seismic action. As a form of passive energy dissipation control, yielding steel shear panel dampers can dissipate energy of the ground motion very well with the plastic deformation. By monotonic cyclic loading, hysteretic performance of the 15 mm thick core-board nonstiffener shear panel damper is tested, and the test shows that the damper has a superior hysteretic performance. Using finite element analysis software ABAQUS, and taking height to thickness ratio of the core-board as variable, the qualitative analysis on the damper is carried out, and results show that the critical height to thickness ratio of shear panel damper is between 30 and 35. Three groups of 15 mm thick core-board nonstiffener shear panel dampers are tested by constant amplitude cyclic loading under different amplitudes; the results show that the fatigue performance is fine and the damper is a good energy dissipation device.
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Shiao, Yao Jung, and Yao Kuan Huang. "Design of a Novel Damping-Controllable Damper for Suspension Systems." Advanced Materials Research 338 (September 2011): 622–25. http://dx.doi.org/10.4028/www.scientific.net/amr.338.622.
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Conventional oil dampers are non-controllable passive dampers because the viscosity of the fluid used is not wide-range variable. By using magneto-rheological fluid (MRF), MRF damper has excellent performance for variable-damping applications. Due to the single-coil design in the general MRF damper, the obtained damping from MR effect is not quite large. This research provides a high-damping MRF damper by adopting multi-pole coil and special polarization configuration. The simulated results show that the new MRF damper has good performance in the magnetic field and damping. Compared with a similar-size general single-coil MRF damper, this new MRF damper can get 47% higher performance under the same operating conditions.
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Yang, Bo, Ao Zhang, Yan Bai, Kuo Zhang, and He Li. "Development and simulation of magnetorheological damper for segment erector vibration control." Transactions of the Canadian Society for Mechanical Engineering 43, no. 2 (June 1, 2019): 237–47. http://dx.doi.org/10.1139/tcsme-2018-0131.
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In this paper, magnetorheological dampers are applied to a segment erector to replace passive vibration dampers. Because magnetorheological damper dynamics are highly nonlinear, design of a direct control system is impossible. To apply linear control theory directly to design the magnetorheological damper controller, the Takagi–Sugeno fuzzy model analytically represents the segment erector model. In addition, a disturbance observer based on a Takagi–Sugeno fuzzy controller is proposed for this system. Both simulations and experiments validate the performance enhancement and stability of the controller. The results show that the acceleration of the segment erector was reduced by 59.6% and 32.1% in oblique wave excitation and random excitation, respectively, compared to a conventional passive damper. The proposed fuzzy controller and magnetorheological dampers have great potential in practical applications because they can significantly improve the performance of a segment erector.
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Shahmohamadi Ousaloo, Hamed. "Hysteresis Nutation Damper for Spin Satellite." Open Aerospace Engineering Journal 6, no. 1 (October 11, 2013): 1–5. http://dx.doi.org/10.2174/1874146001306010001.
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Hysteresis dampers are commonly used in Passive magnetic Attitude Control System (PACS). In PACS these rods produce a damping torque and reduce the satellite angular momentum and angular velocity. In this paper, a spin satellite was investigated which utilizes a passive magnetic damper consisting of magnetic hysteresis rods aligned with principal axis or spin axis of satellite and de-tumbling of the satellite, and the pure spin was achieved. An analytical model was presented to analyze hysteresis damper and a numerical simulation was performed to obtain dynamic properties of the spin attitude. In addition, assuming a dynamic imbalance, attitude behavior and damper effect on the spin rate of satellite were analyzed. The behavior of this passive magnetic stabilized satellite was simulated from the initial post separation phase.
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Thongchom, Chanachai, Ali Ghamari, Ramadhansyah Putra Jaya, and Omrane Benjeddoud. "Experimental and Numerical Study on an Innovative Trapezoidal-Shaped Damper to Improve the Behavior of CBF Braces." Buildings 13, no. 1 (January 5, 2023): 140. http://dx.doi.org/10.3390/buildings13010140.
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Among the existing passive energy dampers, I-shaped shear dampers had shown suitable performance in experimental and numerical studies. Although they improve the dissipating energy and ductility of concentrically braced frames (CBFs), they reduce the stiffness and ultimate strength of the system. Three approaches are generally used to overcome the problem, including (a) increasing the thinness of the shear plates, (b) increasing the number of shear plates, and (c) using more dampers in more bays. The mentioned approaches increase construction costs. Accordingly, to overcome this shortcoming, in this paper, an innovative shear damper with a trapezoidal shape is proposed and investigated experimentally and numerically. The results indicated that when using the same material for I-shaped shear dampers and the proposed damper, the proposed damper has greater ultimate strength, elastic stiffness, and dissipating energy capacity. Additionally, the flange plates are more effective in the behavior of the proposed damper than the I-shaped damper. Moreover, required equations were proposed to design the damper.
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Murín, J., V. Goga, J. Paulech, J. Hrabovský, T. Sedlár, V. Kutiš, and M. Aminbaghai. "Thermo-elastostatic analyzes of new dampers made of polymer springs with negative thermal expansion." IOP Conference Series: Materials Science and Engineering 1199, no. 1 (November 1, 2021): 012056. http://dx.doi.org/10.1088/1757-899x/1199/1/012056.
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Abstract The article presents original results of research of the dampers with passive and semi-active damping using polymer springs (also artificial muscles or nylon springs) with negative thermal expansion. Passive damping can be ensured by the strong damping effects of polymer springs. Semi-active damping can be provided by heating the springs from an additional heat source. According to design such dampers, mathematical models for analytical elastostatic and thermoelastostatic analyzes of dampers for selected load cases are processed in the paper. The permissible values of mechanical and thermal load of the dampers are determined. The obtained results are verified by numerical analysis using the finite element method. The elastostatics of the passive damper and its damping functionality have been verified on a real model of the damper. The compiled mathematical models can be used in the design of polymer dampers as well as in their automatic control. Designed and analysed dampers can be used in smaller mobile or stationary systems such as scooters, small car kits and the like. The elastodynamic functionality of the dampers with passive and semiactive damping will be presented and discussed in our further paper.
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Żurawski, Mateusz, and Robert Zalewski. "Experimental Studies on Adaptive-Passive Symmetrical Granular Damper Operation." Materials 15, no. 17 (September 5, 2022): 6170. http://dx.doi.org/10.3390/ma15176170.
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This paper presents experimental studies on a controllable granular damper, whose dissipative properties are provided by the friction phenomenon occuring between loose granular material. In addition, in order to adjust to the current trends in vibration suppression, we built a semi-active device, controlled by a single parameter—underpressure. Such granular structures subjected to underpressure are called Vacuum-Packed Particles. The first section presents the state of the art. A brief description of the most often used intelligent and smart materials for the manufacture of dampers is presented. The main advantages of the proposed device are a simple structure, low construction cost, symmetrical principle of operation, and the ability to change the characteristics of the damper by quickly and suddenly changing the negative pressure inside the granular core. The second section provides a detailed description of the construction and operation principles of the original symmetrical granular damper. A description of its application in the laboratory research test stand is also provided. The third section presents the results of the experimental studies including the recorded damping characteristics of the investigated damper. The effectiveness of the ethylene–propylene–diene grains’ application is presented. The two parameters of underpressure and frequency of excitation were considered during the empirical tests. The influence of the system parameters on its global dissipative behavior is discussed in detail. The damper operation characteristics are close to linear, which is positive information from the point of view of the potential adaptive-passive control process. Brief conclusions and the prospective application of vacuum-packed particle dampers are presented in the final section.
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Singh, P., S. Gur, and K. Roy. "Seismic Performance of Coupled Buildings Connected by Yield and SMA Dampers." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 1129–37. http://dx.doi.org/10.38208/acp.v1.632.
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Efficient attenuation and control of structural vibration during a seismic event is a critical factor for overall safety and serviceability of the adjacent buildings with little clearance between them. Without proper vibration control measures, adjacent buildings may undergo severe pounding and collapse leading to damage of life and property during an earthquake. Use of energy dissipation devices to connect adjacent buildings has been a popular method of vibration control and to stop mutual poundings. Among various available energy dissipation devices, Shape Memory Alloy (SMA) based dampers are getting popularity in recent time. Various studies are performed to show the efficiency of SMAs as passive vibration control device, but a holistic study of SMA dampers for non-linear connected buildings is still missing. Thus, here a comparative study on the efficiency of metallic yield and super-elastic SMA dampers as passive vibration control device is provided, for non-linear connect buildings. In the present study, non-linear dynamic time history analyses are performed to determine the response (peak floor acceleration and displacement, and floor residual displacement). Time history analyses confirm better acceleration and displacement (both peak and residual) control efficiency of SMA dampers over yield dampers. Finally, superiority of the SMA damper over the yield damper is established via parametric study under varying damper, building and ground motion parameters. Over yield damper, SMA damper reduces acceleration by 13 % to 56 %, displacement by 2 % to 47 %, and residual displacement by 15 % to 64 %.
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Silwal, Baikuntha, Qindan Huang, Osman E. Ozbulut, and Mojtaba Dyanati. "Comparative seismic fragility estimates of steel moment frame buildings with or without superelastic viscous dampers." Journal of Intelligent Material Systems and Structures 29, no. 18 (September 10, 2018): 3598–613. http://dx.doi.org/10.1177/1045389x18798936.
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Superelastic viscous damper is a passive hybrid control device that combines shape memory alloy cables and a viscoelastic damper to mitigate dynamic response of structures subjected to multi-level seismic hazards. In the hybrid device, shape memory alloy cables that exhibit a nonlinear but elastic response are used mainly as re-centering unit, while the viscoelastic damper composed of high-damped butyl rubber compounds is employed to augment the equivalent viscous damping provided by the device. This study evaluates the effectiveness of superelastic viscous dampers in mitigating seismic response of steel frame structures through a probabilistic framework. First, a nine-story steel frame building is designed and modeled with and without superelastic viscous dampers, and extensive nonlinear response-history analyses are conducted. Then, probabilistic demand models are developed for selected engineering demand parameters. To quantitatively compare the performance of the designed buildings, seismic fragility curves and mean annual frequency of exceeding different performance levels are developed. In particular, the structural performance is evaluated using both peak inter-story drift and residual drift responses. Results indicate that superelastic viscous dampers can significantly improve structural performance; thus, it has the potential to lower the post-earthquake losses, as the better structural performance leads to less loss in relocation, rental, and economic loss.
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Guo, Wei, Xiaoli Wu, Xinna Wei, Yao Cui, and Dan Bu. "Inductance effect of passive electromagnetic dampers on building-damper system subjected to near-fault earthquakes." Advances in Structural Engineering 23, no. 2 (August 24, 2019): 320–33. http://dx.doi.org/10.1177/1369433219870579.
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The passive electromagnetic damper was commonly simplified into the linear viscous model in numerical analysis, while this simplification may produce large error when the damper inductance is obvious. In this article, an optimal passive electromagnetic damper with good performance and economy characteristic is proposed by parameter optimization, where the damping density is set as the optimization objective. The hysteresis behavior of the passive electromagnetic damper is verified, and by neglecting the inductance effect, the passive electromagnetic damper can be simplified into the linear viscous model in some cases, but actually the inductance effect is obvious under the high-frequency excitation. Subsequently, the effect of inductance on seismic performance of building damper system under the near-fault earthquake is investigated by comparing the simplified linear viscous model and the accurate passive electromagnetic model. The passive electromagnetic damper was supplemented in a 9-story building, and the analysis of the accurate passive electromagnetic model was carried out by the co-simulation of MATLAB and OpenSees based on the client–server technology. It concludes that the inductance effect is obvious and causes large error when the building damper system is subjected to the near-fault earthquake, and the energy dissipation performance described by the linear viscous model is overestimated.
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Klockiewicz, Zbyszko, and Grzegorz Ślaski. "The Influence of Friction Force and Hysteresis on the Dynamic Responses of Passive Quarter-Car Suspension with Linear and Non-Linear Damper Static Characteristics." Acta Mechanica et Automatica 17, no. 2 (March 19, 2023): 205–18. http://dx.doi.org/10.2478/ama-2023-0024.
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Abstract Vehicle passive suspensions consist of two major elements generating force – spring and passive damper. Both possess non-linear characteristics, which are quite often taken into account in simulations; however, the friction forces inside the hydraulic damper and the damping force’s hysteresis are usually left out. The researchers in this paper present the results of examination of the influence of using complex damper models – with friction and hysteresis; and with linear and non-linear static characteristics – on the chosen dynamic responses of a suspension system for excitations in the typical exploitation frequency range. The results from the simulation tests of the simplified and advanced versions of the damper model – different transfer functions and their relation to the reference model’s transfer functions – are compared. The main conclusion is that friction and hysteresis add extra force to the already existing damping force, acting similar to damping increase for the base static characteristics. But this increase is not linear – it is bigger for smaller frequencies than for higher frequencies. The research shows the importance of including non-linear characteristics and proposed modules in modelling passive dampers.
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Chesné, Simon. "Hybrid skyhook mass damper." Mechanics & Industry 22 (2021): 49. http://dx.doi.org/10.1051/meca/2021050.
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The objective of this study is to increase the efficiency of an initial passive Tuned Mass Damper (TMD) by adding an active control unit. A critical issue in many engineering domains is the design of fail-safe active systems. The proposed hybrid system aims to address this issue and realizes the said objective. It emulates the behavior of a skyhook damper parallel to a passive TMD. Skyhook dampers acts like viscous dampers connected to the ground, reducing the vibration amplitudes without any overshoot. It can be difficult to design a specific control law to obtain a desired dynamical behavior. The paper presents two ways to understand and design the hyperstable control law for Hybrid Mass Damper (HMD) (also called Active TMD), using the power flow formulation or the mechanical impedance analysis. These approaches are illustrated through the synthesis of this hybrid device and the emulation of the Skyhook damper. It is shown that a well-designed control law for this kind of system may result in high damping performance, ensuring stability and a fail-safe behavior. In addition, the amplitude of the primary system’s response is reduced over the entire frequency range which is not the case for the usual active or hybrid systems. Robustness is analyzed and compared to that of the classical active mass damper, and an experimental set up validates the proposed hybrid system.
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Choi, Hyunhoon, and Jinkoo Kim. "New installation scheme for viscoelastic dampers using cables." Canadian Journal of Civil Engineering 37, no. 9 (September 2010): 1201–11. http://dx.doi.org/10.1139/l10-068.
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Passive energy dissipation devices, such as, viscous, viscoelastic, and friction devices are generally installed in buildings using diagonal or chevron braces. To increase the effective damping force and to reduce the damper volume, various magnifying system of the damper displacement, such as, toggle brace system and scissor-jack-damper configuration have been developed with increase in installation cost. In this study, new installation scheme for passive dampers was proposed using cables installed in such a way that relative displacement equal to storey displacement occurs between the cable and the structure when the structure is subjected to lateral load. The cables can be installed continuously or discretely between base and top storey of the structure. To verify the validity of the proposed method nonlinear dynamic analysis of model structures with viscoelastic dampers installed using the proposed configuration scheme was carried out using three earthquake records and two sinusoidal forces. According to the analysis, the proposed method resulted in significant reduction in the size of dampers compared with the conventional installation methods.
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Kijanović, Aleksandar, Milica Mirković Marjanović, and Snežana Ilić. "Ispitivanje otpornosti prema požaru požarno otpornih klapni." Procesna tehnika 34, no. 1 (December 27, 2022): 30. http://dx.doi.org/10.24094/ptc.022.34.1.30.
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Passive fire protection is civil engineering discipline which is very popular for research and development of new construction products and test standards. The primary function of passive fire protection product is to achieve the declared fire resistance. Fire resistance of a construction product is expressed as a time interval (30 min, 60 min, 90 min, 120 min ...) in which certain properties of the tested product are preserved. In the given time intervals, it is necessary for the tested product to maintain the thermal insulation properties (I), integrity (E) and additional properties prescribed by the test standard related to the tested product. The fire damper represents part of HVAC system installed on walls which are fire resistance barriers [2]. Additional properties related to fire-resistant service installations- fire dampers (hereinafter only fire dampers) are the leakage on the fire damper in the cold state and the leakage of fire damper (S) during the fire test. In order to determine the previous properties, a test installation for fire dampers was formed, which consists of: installed damper in the test wall, duct and pipeline system, system for measuring the volume flow, cooler and a fan. All the obtained results are graphically presented in the paper and serve for the purpose of determining the mentioned fire properties of dampers and for the purpose of fire resistance classification of construction products.
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Miao, Fei, Faezeh Nejati, Sulima Ahmed Mohammed Zubair, and Mona Elmahi Yassin. "Seismic Performance of Eccentrical Braced Frame Retrofitted by Box Damper in Vertical Links." Buildings 12, no. 10 (September 22, 2022): 1506. http://dx.doi.org/10.3390/buildings12101506.
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Passive control methods reduced the vulnerability of structures to earthquakes by decreasing the seismic demand and improving structural plasticity. One of the passive control systems is the eccentrically braced frame with a vertical shear link (V-EBF). The present study aims to direct the damage to the absorbing plates of the vertical link beam to allow the structure’s appropriate seismic performance and reparability. Yielding dampers are one of the most widely used types in systems and can provide perfect vibration control if used optimally. Different types of dampers were introduced and used; how to use them depends on the shape and the way they connect to the structure. This research investigates a new type of damper called box damper, an improved type of shear panel damper. The improvement in the way of connecting to the braced frame and the ease of using this damper in different situations are the features of this new damper. This research investigated the mechanism of these yielding dampers in structures and their strengths and weaknesses. In the next step in this study, a V-EBF with plates of thickness 4, 6, and 8 mm was analysed in the finite element software ABAQUS using the nonlinear static analysis and cyclic loading conditions. Some examples of this damper were attached to the braced frames to investigate the effect of using this damper on the seismic behaviour of the braced structures. The results show that the shear link performs like an electrical fuse absorbing all damage and plastic hinges so that other elements of the braced frame remain in their nonlinear elastic region. By increasing the thickness of the damper from 2 to 8 mm, the resistance increased by two times, and the flexibility of the structure had a noticeable change with the rise in thickness from 2 mm to 8 mm. Ductility increased from 38 to 75 mm.
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Dargush, G. F., and T. T. Soong. "Behavior of Metallic Plate Dampers in Seismic Passive Energy Dissipation Systems." Earthquake Spectra 11, no. 4 (November 1995): 545–68. http://dx.doi.org/10.1193/1.1585827.
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Metallic plate dampers, when incorporated into a structure, provide one of the most effective energy dissipation mechanisms available during an earthquake. Increasingly, they are applied in the seismic retrofit of structures which are found to be deficient. The design of these devices, however, has been largely based upon experiments and macroscopic modeling. In order to gain more insight into the response behavior of metallic plate dampers, a microscopic mechanistic approach is followed in this paper. Included is the development of an inelastic constitutive model for the damper material. Numerical results obtained for a class of metallic plate dampers are presented and comparisons are made with experimental data for validation of the mathematical model. It is also shown that this approach sheds light on several aspects of the damper response which heretofore have not been addressed adequately.
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Nordin, NH Diyana, Asan GA Muthalif, and M. Khusyaie M Razali. "Control of transtibial prosthetic limb with magnetorheological fluid damper by using a fuzzy PID controller." Journal of Low Frequency Noise, Vibration and Active Control 37, no. 4 (April 8, 2018): 1067–78. http://dx.doi.org/10.1177/1461348418766171.
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The damping characteristic of a healthy limb changes throughout the gait cycle. However, for amputees who are wearing mechanically passive damping prosthesis, the lack of ability to change the damping values might expose them to injuries and health problems. The use of magnetorheological fluid damper in prosthetic limb, which provides wide dynamic range, seems to be able to prevent these conditions from happening, due to its response to the magnetic field. The magnetorheological fluid, a type of smart material that is capable of altering its rheological property, changes its viscosity subjected to the intensity of the external magnetic field. Thus, due to this property, magnetorheological fluid damper covers the advantages of both passive and active dampers. This work explores the implementation of magnetorheological fluid damper in transtibial (below knee) prosthetic limb utilizing adaptive control techniques via simulation studies. An experimental study was done to observe the relationship of the force generated by the damper to the applied current. In addition, fuzzy-proportional–integral–derivative controller was implemented to ensure that the damper performs well, even at varying frequencies.
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Lau, Y. K., and W. H. Liao. "Design and Analysis of Magnetorheological Dampers for Train Suspension." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 219, no. 4 (July 1, 2005): 261–76. http://dx.doi.org/10.1243/095440905x8899.
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This article aims at designing a magnetorheological (MR) fluid damper that is suitable for a semi-active train suspension system in order to improve its ride quality. A double-ended MR damper is designed, fabricated, and tested. Simulation is carried out by integrating the MR damper model in the secondary suspension of a full-scale railway vehicle model. The feasibility and effectiveness of the semi-active train suspension system with the developed MR dampers are investigated by comparing the controlled performances of the MR suspension system with different passive suspension systems. The results show that the semi-active suspension with the developed MR dampers can substantially improve the ride quality of the passengers.
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Kontoni, Denise‐Penelope N., Ali Ghamari, Javad Kheiri, and Georgios Ilia. "An innovative I‐shaped low‐yield steel shear damper directly connected to the concentrically braced frame." ce/papers 6, no. 3-4 (September 2023): 925–29. http://dx.doi.org/10.1002/cepa.2604.
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AbstractShear dampers are known as famous seismic passive energy devices due to their suitable performance against seismic loading to improve the behavior of Concentrically Braced Frames (CBFs). The CBF system suffers from low ductility due to its compression member's susceptibility to buckling. By adding the shear dampers directly to the diagonal element members of the CBF, the dampers prevent the bucking of the CBF and improve the behavior of the system. Although the dampers pertain to high energy dissipation capacity, they reduce the ultimate strength and elastic stiffness of the system. To overcome the shortcoming, in this paper, utilizing low‐yield point steel to create an I‐shaped damper is proposed and investigated parametrically and numerically by the Finite Element Method (FEM). This damper is directly connected to the CBF's diagonal member. The results indicated that by using the proposed I‐shaped damper, the ultimate strength, elastic stiffness, and energy dissipation of the system are enhanced. Also, the damper prevents the bucking of the CBF, which causes the damages to be limited in the damper, and the CBF to remain in the elastic zone. Also, required equations were suggested to design the system.
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Patel, C. C. "Seismic Response Control of Parallel Structures Connectd by Passive Shape Memory Alloy Damper." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 583–89. http://dx.doi.org/10.38208/acp.v1.552.
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A shape Memory Alloys are a class of novel functional materials that possess unique properties, including shape memory effect, super-elasticity effect, high damping characteristics, high corrosion resistance, temperature dependent Young modulus and extra ordinary fatigue resistance. In super-elastic phase, shape memory alloys are initially austenitic, upon loading, stress-induced martensite is formed, upon unloading, the martensite reverts to austenite at a lower stress level, resulting in the hysteretic behaviour, is more suitable property for energy dissipation device in structural engineering. In this paper, the response behaviour of two parallel structures coupled by passive Shape Memory Alloy dampers under various earthquake ground motion excitations is investigated. The equation of motion for the two parallel, single-degree-of-freedom structures connected by damper is formulated. The effectiveness of damper in terms of the structural response reduction namely, relative displacement and absolute acceleration of coupled structure is investigated. A parametric study is conducted to investigate the optimum parameter of the dampers. Results show that Shape Memory Alloy dampers connecting the parallel structures of different fundamental frequencies, the earthquake induced displacement response of either structure can be reduce effectively, but acceleration response of flexible structure is increases. Thus passive shape memory alloy damper is not much effective for seismic protection of coupled structure concept.
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Nguyen, Phuc Quang Bao, Hoa Nhan Pham, and Thang Quoc Chu. "COMPARE THE EFFICIENCY OF CONTROLLED STIFFNESS DAMPER WITH VARIABLE FRICTION DAMPER FOR SEISMIC PROTECTION OF BUILDING." Science and Technology Development Journal 12, no. 8 (April 28, 2009): 81–89. http://dx.doi.org/10.32508/stdj.v12i8.2277.
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The implementation of variable friction dampers (VFD) for vibration mitigation of seismic structures generally requires an efficient semi-active control law. In this paper, a semi-active modal control method is proposed to determine the controllable clamping force of a variable friction damper. A comparative study was performed on a multiple DOF structure controlled by passive friction dampers, variable friction dampers in subsection numerical examples. Finally, this paper also provides preliminary conclusions about the advantages and disadvantages for friction dissipators.
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Chen, Bo, Xiang Xiao, Peng-yun Li, and Wan-li Zhong. "Performance Evaluation on Transmission Tower-Line System with Passive Friction Dampers Subjected to Wind Excitations." Shock and Vibration 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/310458.
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The vibration control and performance evaluation on a transmission-tower line system by using friction dampers subjected to wind excitations are carried out in this study. The three-dimensional finite element (FE) model of a transmission tower is firstly constructed. A two-dimensional lumped mass model of a transmission tower is developed for dynamic analysis. The analytical model of transmission tower-line system is proposed by taking the dynamic interaction between the tower and the transmission lines into consideration. The mechanical model of passive friction damper is presented by involving the effects of damper axial stiffness. The equation of motion of the transmission tower-line system incorporated with the friction dampers disturbed by wind excitations is established. A real transmission tower-line system is taken as an example to examine the feasibility and reliability of the proposed control approach. An extensive parameter study is carried out to find the optimal parameters of friction damper and to assess the effects of slipping force axial stiffness and hysteresis loop on control performance. The work on an example structure indicates that the application of friction dampers with optimal parameters could significantly reduce wind-induced responses of the transmission tower-line system.
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Sharma, Sunil Kumar, and Anil Kumar. "Ride comfort of a higher speed rail vehicle using a magnetorheological suspension system." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 232, no. 1 (May 2, 2017): 32–48. http://dx.doi.org/10.1177/1464419317706873.
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In a railway vehicle, vibrations are generated due to the interaction between wheel and track. To evaluate the effect of vibrations on the ride quality and comfort of a passenger vehicle, the Sperling's ride index method is frequently adopted. This paper focuses on the feasibility of improving the ride quality and comfort of railway vehicles using semiactive secondary suspension based on magnetorheological fluid dampers. Equations of vertical, pitch and roll motions of car body and bogies are developed for an existing rail vehicle. Moreover, nonlinear stiffness and damping functions of passive suspension system are extracted from experimental data. In view of improvement in the ride quality and comfort of the rail vehicle, a magnetorheological damper is integrated in the secondary vertical suspension system. Parameters of the magnetorheological damper depend on current, amplitude and frequency of excitations. Three semi-active suspension strategies with magnetorheological damper are analysed at different running speeds and for periodic track irregularity. The performance indices calculated at different semi-active strategies are juxtaposed with the nonlinear passive suspension system. Simulation results establish that magnetorheological damper strategies in the secondary suspension system of railway vehicles reduce the vertical vibrations to a great extent compared to the existing passive system. Moreover, they lead to improved ride quality and passenger comfort.
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Palacios-Quiñonero, Francisco, Josep Rubió-Massegú, Josep M. Rossell, and Hamid Reza Karimi. "Distributed Passive Actuation Schemes for Seismic Protection of Multibuilding Systems." Applied Sciences 10, no. 7 (March 31, 2020): 2383. http://dx.doi.org/10.3390/app10072383.
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In this paper, we investigate the design of distributed damping systems (DDSs) for the overall seismic protection of multiple adjacent buildings. The considered DDSs contain interstory dampers implemented inside the buildings and also interbuilding damping links. The design objectives include mitigating the buildings seismic response by reducing the interstory-drift and story-acceleration peak-values and producing small interbuilding approachings to decrease the risk of interbuilding collisions. Designing high-performance DDS configurations requires determining convenient damper positions and computing proper values for the damper parameters. That allocation-tuning optimization problem can pose serious computational difficulties for large-scale multibuilding systems. The design methodology proposed in this work—(i) is based on an effective matrix formulation of the damped multibuilding system; (ii) follows an H ∞ approach to define an objective function with fast-evaluation characteristics; (iii) exploits the computational advantages of the current state-of-the-art genetic algorithm solvers, including the usage of hybrid discrete-continuous optimization and parallel computing; and (iv) allows setting actuation schemes of particular interest such as full-linked configurations or nonactuated buildings. To illustrate the main features of the presented methodology, we consider a system of five adjacent multistory buildings and design three full-linked DDS configurations with a different number of actuated buildings. The obtained results confirm the flexibility and effectiveness of the proposed design approach and demonstrate the high-performance characteristics of the devised DDS configurations.
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Xu, Yeshou, Zhaodong Xu, Yingqing Guo, Xinghuai Huang, Yaorong Dong, and Qiangqiang Li. "Dynamic Properties and Energy Dissipation Study of Sandwich Viscoelastic Damper Considering Temperature Influence." Buildings 11, no. 10 (October 13, 2021): 470. http://dx.doi.org/10.3390/buildings11100470.
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Viscoelastic dampers are a kind of classical passive energy dissipation and vibration control devices which are widely utilized in engineering fields. The mechanical properties and energy dissipation capacity of the viscoelastic damper are significantly affected by ambient temperature. In this work, dynamic properties tests of the sandwich type viscoelastic damper at different environmental temperatures are carried out. The equivalent fractional Kelvin model which can characterize the mechanical behavior of the viscoelastic damper with varying frequencies and temperatures is introduced to describe the dynamic properties and energy dissipation capability of the sandwich viscoelastic damper. The self-heating phenomenon of the sandwich viscoelastic damper is studied with a numerical simulation, and the dynamic properties and energy dissipation variation of the viscoelastic damper with self-heating processes are also analyzed. The results show that the dynamic properties of the viscoelastic damper are significantly affected by temperature, excitation frequency and the internal self-generated heating.
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Kado, Naohiro. "Theoretical and numerical studies of semi-active friction damper showing viscous-damper-like characteristics." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 10 (May 24, 2017): 1778–85. http://dx.doi.org/10.1177/0954406217710304.
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To clarify the feasibility of a novel, semi-active friction damper, its damping characteristics were investigated theoretically and numerically. The proposed damper suppresses vibrations by changing the direction of the frictional force, in contrast to the conventional passive and semi-active friction dampers that only focus on the magnitude of the frictional force. The theoretical analysis indicates that the proposed damper can behave as a conventional friction damper or a viscous damper depending on the use conditions; further, its effective damping ratio can be controlled by the velocity of a friction plate moving in a direction orthogonal to the direction of the vibration. The numerical simulations clarified that damping characteristics can be controlled by the ratio of the amplitude of the excitation force to the frictional force. Finally, the design criteria of the proposed damper were derived.
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FACEY, WILLIAM B., NICHOLAS C. ROSENFELD, YOUNG-TAI CHOI, NORMAN M. WERELEY, SEUNG BOK CHOI, and PETER CHEN. "DESIGN AND TESTING OF A COMPACT MAGNETORHEOLOGICAL DAMPER FOR HIGH IMPULSIVE LOADS." International Journal of Modern Physics B 19, no. 07n09 (April 10, 2005): 1549–55. http://dx.doi.org/10.1142/s0217979205030578.
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Magnetorheological (MR) based semi-active dampers for the protection of sensitive devices against high shock and impact is examined from design considerations to characterization testing. Shock and impact dampers should be able to produce a high damping force at high velocities. However, a specification requiring high damping force generally causes an increase in the size of shock and impact dampers, which motivates the study of MR dampers to retrofit existing or conventional passive shock and impact dampers. A novel MR damper design was developed in this study for achieving both design goals: high force and compactness. The novel MR damper design increases the number of magnetically active volumes through which fluid to passes while minimizing damper length. Through FEM (Finite Element Method) analysis, the magnetic properties of the proposed design are investigated prior to actual fabrication. In addition to the unique magnetic circuit, other considerations stemming from the high pressures and velocities expected in this device are addressed. Characterization testing was performed up to 12 Hz with 1 inch sinusoidal stroke on a servo-hydraulic testing machine. These tests demonstrate that the MR damper is able to provide a high damping force at high velocity.
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Madgounkar, Sachin Sunil, Naveen Kumar H. S, and Chethan Gowda R. K. "Comparative Study on Seismic Behavior of High–Rise Steel Building with and Without Friction Damper and Fluid Viscous Damper: A Review." International Journal for Research in Applied Science and Engineering Technology 10, no. 8 (August 31, 2022): 1649–53. http://dx.doi.org/10.22214/ijraset.2022.46373.
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Abstract: Seismic forces are induced on the structure present in earthquake prone areas. These are induced due to the movement of tectonic plates. Multi-storey buildings are those that have more than two stories, hence undergo large amount of deflection due to their slender structure. Due to the deflection caused by the ground accelerations during earthquakes, the structure is unstable and the structure undergoes damage which is not safe. Passive energy dissipation devices are gaining significance in design of earthquake resistant structures because of their effective performance in controlling seismic effects on structures during earthquake. Friction dampers and fluid viscous damper are passive energy dissipating devices which are used widely as seismic control devices. The present study was conducted analytically on a 15-storey steel frame with regular and irregular configuration and performance of structure against non-linear time history ground movement with and without friction damper and fluid viscous damper. Time history ground acceleration data of Bhuj earthquake (2001) were applied on the structure and the response of friction damper and fluid viscous damper was analyzed and compared. The analysis of the structure for the non-linear dynamic ground acceleration was conducted using ETABS software. The results show that when a friction damper is used instead of a fluid viscus damper, storey displacement is greatly reduced by 25.52%. whereas results shows that storey shear, storey drift, and storey acceleration are greatly reduced by 27.75%, 30.39% and 15.27%, when fluid viscous damper is used instead of a friction damper.
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Rashid, Mohd Mahbubur, Momoh J. E. Salami, M. Raisuddin K., and R. Mozasser. "Development of Vibration Suppression Devices from Smart Fluids." Advanced Materials Research 264-265 (June 2011): 548–53. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.548.
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Semi-active control devices have received significant attention in recent years because they offer the adaptability of active control devices without requiring the associated large power sources. Magneto-rheological (MR) dampers are semi-active control devices that use MR fluids to produce controllable dampers. They potentially offer highly reliable operation and can be viewed as fail-safe in that they become passive dampers should the control hardware malfunction. To develop control algorithms that take maximum advantage of the unique features of the MR damper, models must be developed that can adequately characterize the damper’s intrinsic nonlinear behavior. Following a review of several idealized mechanical models for controllable fluid dampers, a model is proposed that can effectively portray the behavior of a typical magneto-rheological damper. Comparison with experimental results for a prototype damper indicates that the model is accurate over a wide range of operating conditions and is adequate for control design and analysis.
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JO, Hoonhee, Hiroshi YABUNO, Yuki SAKAI, and Tosiyuki KANAKUBO. "106 Vibration Control by a Passive Nonlinear Damper." Proceedings of the Dynamics & Design Conference 2006 (2006): _106–1_—_106–6_. http://dx.doi.org/10.1299/jsmedmc.2006._106-1_.
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Arsava, K. Sarp, and Yeesock Kim. "Modeling of Magnetorheological Dampers under Various Impact Loads." Shock and Vibration 2015 (2015): 1–20. http://dx.doi.org/10.1155/2015/905186.
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Magnetorheological (MR) damper has received great attention from structural control engineering because it provides the best features of both passive and active control systems. However, many studies on the application of MR dampers to large civil structures have tended to center on the modeling of MR dampers under seismic excitations, while, to date, there has been minimal research regarding the MR damper model under impact loads. Hence, this paper investigates nonlinear models of MR dampers under a variety of impact loads and control signals. Two fuzzy models are proposed for modeling the nonlinear impact behavior of MR dampers. They are compared with mechanical models, the Bingham and Bouc-Wen models. Experimental studies are performed to generate sets of input and output data for training, validating, and testing the models: the deflection, acceleration, velocity, and current signals. It is demonstrated that the proposed fuzzy models are effective in predicting the complex nonlinear behavior of the MR damper subjected to a variety of impact loads and control signals. The proposed fuzzy model resulted in an accuracy of 99% to predict the impact forces of the MR damper.
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Ummati, Alfinna Mahya, Nugraha Bintang Wirawan, and Hendra Halim. "Curved Damper as Structural Retrofitting Element to Improve the Performance of Steel Truss Bridge." Rekayasa Sipil 18, no. 1 (February 20, 2024): 1–6. http://dx.doi.org/10.21776/ub.rekayasasipil.2024.018.01.1.
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The curved damper can control the structure movement by a physical approach to reduce the lateral deformation under the earthquake, which previously proved to be a significant improvement when applied on a moment-resisting frame in a laboratory scale experiment. With the same idea, a curved damper is considered a passive control to reduce the excessive deformation for a single span of a steel truss bridge, which is analyzed by finite element modeling to evaluate the role of the curved damper in a complex structure. The study of curved dampers applied in this typical bridge showed that mid-span deformation can be mitigated by up to 62% under an earthquake. Hence, a structure with a curved damper is recommended for application in high seismic locations.
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Nikooyan, A. A., and A. A. Zadpoor. "Mass–spring–damper modelling of the human body to study running and hopping – an overview." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 225, no. 12 (October 7, 2011): 1121–35. http://dx.doi.org/10.1177/0954411911424210.
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Several mass–spring–damper models have been developed to study the response of the human body to the collision with the ground during hopping, trotting, or running. The mass, spring, and damper elements represent the masses, stiffness properties, and damping properties of hard and soft tissues. The masses that models are composed of are connected to each other via springs and dampers. The present paper reviews the various types of mass–spring–damper models including one-body and multi-body models. The models are further categorized as being either passive or active. In passive models, the mechanical properties (stiffness and damping) of soft tissues remain constant regardless of the type of footwear, ground stiffness, etc. In active models, the mechanical properties adapt to external loads. The governing equations of motion of all models as well as their parameters are presented. The specific ways that the models take account of the shoe–ground interactions are discussed as well. The methods used for determination of different modelling parameters are briefly surveyed. The advantages and disadvantages of the different types of mass–spring–damper models are also discussed. The paper concludes with a brief discussion of possible future research trends in the area of mass–spring–damper modelling.
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Luong, Quoc Viet, Dae-Sung Jang, and Jai-Hyuk Hwang. "Robust Adaptive Control for an Aircraft Landing Gear Equipped with a Magnetorheological Damper." Applied Sciences 10, no. 4 (February 21, 2020): 1459. http://dx.doi.org/10.3390/app10041459.
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A landing gear of an aircraft is required to function at touchdown in different landing scenarios with parametric uncertainties. A typical passive damper in a landing gear has limited performance in differing landing scenarios, which can be overcome with magnetorheological (MR) dampers. An MR damper is a semi-active system that can adjust damping force by changing the amount of electric current applied to it. This paper proposes a new robust controller based on model reference sliding mode control and adaptive hybrid control to improve the efficiency of absorbing landing impact energy, not only considering the variables of aircraft weight and sink speed but also managing uncertainties, such as ambient temperature and passive damping coefficient. To verify the effectiveness of the proposed controller, comparative numerical simulations were performed with a passive damper, a skyhook controller, and the proposed controller under various landing scenarios. The simulation results show that the proposed controller improves the total energy absorber efficiency by up to 10% higher than that of the skyhook controller. In addition, the proposed controller is demonstrated to have better adaptability and robustness than the other control algorithms in the differing landing scenarios and parametric uncertainties.
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As’arry, A., M. F. Idrus, K. L. Zhang, K. A. M. Rezali, and M. N. Hassan. "Integration of Skyhook Control in a Quarter Car with Magnetorheological (MR) Damper." Journal of Physics: Conference Series 2721, no. 1 (March 1, 2024): 012019. http://dx.doi.org/10.1088/1742-6596/2721/1/012019.
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Abstract Semi-active suspension (SAS) systems attenuate vibrations with minimal power Consumption and is usually paired with magnetorheological (MR) dampers which are a type of variable damper that produces high damping forces with no mechanical movement. This paper presents the analysis of a Skyhook controller in a quarter car test rig equipped with MR damper to reduce vibration peaks when excited by a sinusoidal signal which simulates the unevenness of road surfaces. The viability of Skyhook control in mitigating vibration was examined from the experiments. The study discovered that there was an improvement of 12.72% by Skyhook control when compared to passive damping based on the sprung mass acceleration of both damping modes. The Skyhook controller surpassed passive damping and was deemed a success in vibration control.
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Hayashi, Motoya, Hoon kim, Yoshinori Honma, and Junichiro Matsunaga. "Feasibility of a Passive Ventilation System with a Thermal Damper - Simulations and measurement results of an experimental house in a mild region of Japan -." E3S Web of Conferences 111 (2019): 06047. http://dx.doi.org/10.1051/e3sconf/201911106047.
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In order to retain good indoor air quality through the year in detached houses with passive ventilation systems, the authors investigated a mechanical control air-supply method. Firstly, indoor environments in houses with passive ventilation systems with thermal dampers, were examined using a simulation program (Fresh). Secondly, a passive ventilation system with a thermal damper, an under-floorheating system with a heat pump and were installed in an airtight house at Maebashi in Japan and measurements on its ventilation characteristics and indoor air quality were made. The simulation results showed that if the thermal damper is well tuned, this mechanically controlled air-supply opening keeps ventilation rates adequate through the year especially in airtight houses. The measurement results showed that the ventilation rates were kept above the required level through the year and the TVOC concentration decreases from 3000 to 200 μg/m3 in 5 months after the construction.
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Parulekar, Y. M., G. R. Reddy, K. K. Vaze, and K. Muthumani. "Passive Control of Seismic Response of Piping Systems." Journal of Pressure Vessel Technology 128, no. 3 (August 30, 2005): 364–69. http://dx.doi.org/10.1115/1.2217969.
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Passive energy dissipating devices, such as elastoplastic dampers (EPDs) can be used for eliminating snubbers and reducing the response of piping systems subjected to seismic loads. Cantilever and three-dimensional piping systems were tested with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping systems supported on elastoplastic damper. An iterative response spectrum method is used for evaluating response of the piping system using this equivalent damping. The analytical maximum response displacement obtained at the elastoplastic damper support for the two piping systems is compared with experimental values and time history analysis values. It has been concluded that the iterative response spectrum technique using Caughey equivalent damping is simple and results in reasonably acceptable response of the piping systems supported on EPD.
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Li, Peng Yun, An Guo Huang, and Chun Xia. "Dynamic Energy of Building under Earthquake Excitation Based on FEM." Advanced Materials Research 255-260 (May 2011): 2998–3002. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.2998.
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Evaluation on dynamic energy characteristics of building under earthquake excitation with passive friction damper-protected devices based on finite element method (FEM) is actively carried out in this study. The mechanical model of the dampers is first introduced and the dynamic model of building-damper system is proposed. The evaluation criteria of energy responses are developed and applied to the earthquake response mitigation of a real multi-story building incorporated with friction dampers. The results indicate that the earthquake-induced vibration of the building can be substantially suppressed and the proposed energy evaluation criteria can be effectively utilized in the examination on seismic mitigation performance.
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Lee, Sang-Hyun, Kyung-Jo Youn, and Kyung-Won Min. "A decentralized response-dependent MR damper for controlling building structures excited by seismic load." Journal of Intelligent Material Systems and Structures 22, no. 16 (August 17, 2011): 1913–27. http://dx.doi.org/10.1177/1045389x11417197.
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In this study, a decentralized algorithm for operating a semiactive MR damper was presented. The frictional force of the MR damper was determined based on the assumed shape functions using the displacement and velocity of the damper piston itself. The seismic response control performance of the MR damper was numerically and experimentally evaluated and compared to that of the passively or semiactively operated MR damper. The results from numerical analysis of SDOF system indicated that passively operated MR damper to have an optimal frictional force less than about 30% of the base shear force provided the smallest displacement response spectrum over all the periods. The proposed MR damper showed the better performance in reducing the absolute acceleration with the larger frictional force than the passive one. Also, the results from a three-storey benchmark building indicated that the proposed decentralized MR damper provided control performance equivalent to or better than the performance shown by the semiactive MR damper using a centralized LQR algorithm. Finally, the effectiveness of the proposed MR damper was verified through experimental tests of a full-scale five-storey steel structure with the MR dampers.