A novel semi-active TMD with folding variable stiffness spring

Rafieipour, M. H.; Ghorbani‐Tanha, Amir K.; Rahimian, M.; Mohammadi-Ghazi, Reza

doi:10.1007/s11803-014-0258-5

Cited by 16 publications

(16 citation statements)

References 11 publications

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“…27 Recently, Rafieipour et al have proposed an apparatus consisted of a folding variable stiffness spring. 28 Besides, Wu and Lan have investigated a wide range of variable stiffness mechanisms for semiactive TVAs, 29 and Williams et al have utilized shape memory alloys in this regard. 30 Recently, Asai et al have proposed a new variable stiffness TVA, which is equipped with an electromagnetic transducer and whose inertial mass is supplied by a ball-screw mechanism.…”

Section: Thenmentioning

confidence: 99%

“…Later, based upon the effective stiffness of a variable moment of inertia beam, Ghorbani‐Tanha propounded the idea of another adaptive device . Recently, Rafieipour et al have proposed an apparatus consisted of a folding variable stiffness spring . Besides, Wu and Lan have investigated a wide range of variable stiffness mechanisms for semiactive TVAs, and Williams et al have utilized shape memory alloys in this regard .…”

Section: Introductionmentioning

confidence: 99%

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An innovative adaptive tuned vibration absorber with variable mass moment of inertia for mitigation of transient response of systems

Shakib

Ghorbani‐Tanha

2020

Struct Control Health Monit

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Summary An innovative semiactive device, named the spindle adaptive tuned vibration absorber (SATVA), is proposed herein, having the potential of attenuating unfavorable vibrations of the host systems. The proposed device includes a preferably spindle‐shaped body of mass, whose mass moment of inertia can be altered simply by moving a pair of rotating supports. Therefore, the natural frequency of the device can be altered with a fairly low power consumption. A comprehensive analytical approach is employed in order to derive the governing equations of motion of the device, considering physical and practical issues. Through a numerical case study, it is demonstrated that the device is capable of reducing unfavorable vibrations of a rotating machinery during start‐up, while requiring considerably less amount of physical mass, compared with conventional absorbers. In addition, the spindle adaptive tuned vibration absorber has a quite rapid adaptation mechanism in comparison with other adaptive‐mass tuned vibration absorbers. Provided that its absolute acceleration during operation can be kept within reasonable limits to prevent slipping, this device is capable of finding different applications in various engineering disciplines.

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Section: Thenmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An innovative adaptive tuned vibration absorber with variable mass moment of inertia for mitigation of transient response of systems

Shakib

Ghorbani‐Tanha

2020

Struct Control Health Monit

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“…The variable stiffness incorporated in the PCRTMD strategy is a continuously variable system, which is able to adjust the stiffness of the TMD smoothly and continuously whenever needed. Toward this aim, several proposed mechanisms could be implemented in the PCRTMD strategy; among them are the semiactive variable stiffness control (SAIVS) device proposed by Nagarajaiah and the folding variable stiffness spring . The SAIVS consists of four springs with telescoping elements that are set in a rhombus configuration; a DC servomotor (electromechanical actuator) controls the SAIVS and is able to change the aspect ratio of the rhombus, thus changing the stiffness of the device between a minimum and a maximum value.…”

Section: Physical Setup Of the Pcrtmd Motion Equations And Control mentioning

confidence: 99%

Performance evaluation of phase‐controlled semiactive resettable TMD (PCRTMD) with the stiffness retuning ability under strong seismic motions

Amini

Tourani

Ghaderi

2018

Structural Design Tall Build

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Summary Tuned mass dampers (TMDs), despite being efficient because the structure has not experienced damage and properties degradation, lose efficiency when the mechanical properties of the structure changes and detuning effects occur. Semiactive TMDs have been shown superior to the traditional passive ones and more efficient and reliable than the active counterparts for the detuning problem. This study presents a novel semi active system that is able to respond efficiently and maintain such a performance even in the case of structural damage. This scheme is composed of a variable stiffness component, a resettable element, and a friction brake. The system dissipates energy using the resetting mechanism and is able to change stiffness when the tuned frequency of the structure changes due to structural damage. The friction device is responsible for maintaining the TMD in the optimal phase lag to the structure, that is, −90°, and thus keeping the TMD in the optimal performance. This strategy has been tested on a single‐degree‐of‐freedom frame, to understand the system behavior under harmonic excitation, as well as a 10‐story shear type frame under strong seismic motions. The proposed system has shown to be effective and competent comparing analysis results to active and passive TMDs.

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“…Kamgar, Samea, and Khatibinia optimized TMDs by a critical excitation method employing improved gravitational search algorithm. In addition to classical TMD consisting of a mass, stiffness elements, and dampers, other types of TMD including nonlinear viscous damping, semi‐active TMD, hybrid TMD, eddy‐current TMD, particle TMD, and compound TMD have been also proposed.…”

Section: Introductionmentioning

confidence: 99%

Optimum design of multiple positioned tuned mass dampers for structures constrained with axial force capacity

Niğdeli

Bekdaş

2019

Structural Design Tall Build

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The stories of structure may have different and limited axial force capacity. In order to passively control the translational movement of structures, a tuned mass damper (TMD) positioned on a story may cause to exceed axial force capacity of a story.The optimum performance is achieved when all additional masses are positioned on the top story. Whereas, the top stories of structure may be constructed with lower axial force capacity than the lower stories. In that case, the maximum allowed TMD mass for upper stories may be low. In that situation, several TMDs may be positioned on several stories. In the current study, the optimum tuning of TMDs positioned on multiple stories of structure is investigated. By using small masses, it is also possible to obtain effective passive control with dampers that have small damping coefficients comparing with a single TMD on the top of the structure. The design variables of the optimization problem such as the period and damping ratio of TMD are tuned according to a metaheuristic algorithm called flower pollination algorithm. The TMD is optimized for near-fault excitations by using impulsive motions during the optimization process. The proposal was applied to four case studies. According to the results, the multiple positioned TMDs may be a practical and effective option comparing with the use of a single heavy TMDs on the top of a structure. KEYWORDS axial force, flower pollination algorithm, impulsive motions, optimization, optimum tuning, tuned mass dampers | INTRODUCTIONIn order to reduce structural vibrations originating from seismic sources, tuned mass dampers (TMDs) can be used, but the mass of the TMD must be too big to provide an effective performance on the lateral responses of the structure. Although the responses are positively affected, the fracture or ductility limit (especially for reinforced concrete structures) of vertical structural members (columns) can be exceeded. In that situation, the structural capacity must be considered as the mass limit or the structure must be retrofitted for increasing the axial force capacity. In a civil structure, the forces of upper stories are directed to a lower story. In that case, the axial force is the maximum at the lowest story. For that reason, upper stories of civil structures may be constructed by smaller cross-sections and less reinforcements than the lower stories. In that case, the axial force capacity of upper stories may be less than the capacity of the lower stories. Generally, the optimum position of a TMD is the top of the building where the first mode shape value is the maximum for the critical mode of the structure. In that case, the number of TMDs can be increased and small TMDs can be placed on multiple stories.The most important performance index of TMDs is the optimum tuning. By using multiple TMDs on different stories, it will be a more challenging optimization problem. For this problem, to use a well-known optimum frequency and damping ratio formulation will not be effective because these formulations wer...

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A novel semi-active TMD with folding variable stiffness spring

Cited by 16 publications

References 11 publications

An innovative adaptive tuned vibration absorber with variable mass moment of inertia for mitigation of transient response of systems

An innovative adaptive tuned vibration absorber with variable mass moment of inertia for mitigation of transient response of systems

Performance evaluation of phase‐controlled semiactive resettable TMD (PCRTMD) with the stiffness retuning ability under strong seismic motions

Optimum design of multiple positioned tuned mass dampers for structures constrained with axial force capacity

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