Estimation of the modal mass of a structure with a tuned-mass damper using H-infinity optimal model reduction

2006 ◽  
Vol 28 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Jae-Seung Hwang ◽  
Hongjin Kim ◽  
Jinkoo Kim
Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Md Motiur Rahman ◽  
Tahmina Tasnim Nahar ◽  
Dookie Kim

This paper investigates the performance of tuned mass damper (TMD) and dynamic behavior of TMD-controlled concrete structure considering the ground motion (GM) characteristics based on frequency content. The effectiveness of TMD in reducing the structural response and probability of collapse of the building frames are affected by the frequency characteristics of GMs. To attenuate the seismic vibration of the buildings, the TMD controlled building has been designed based on the modal analysis (modal frequencies and modal mass participation ratio). In this study, to investigate the performance of TMD, four different heights (i.e., 3, 5, 10, 20 stories) inelastic concrete moment-resisting frames equipped with TMDs are developed using an open-source finite element software. A series of numerical analyses have been conducted using sixty earthquakes classified into three categories corresponding to low, medium, and high-frequency characteristics of GMs. To evaluate the proposed strategy, peak lateral displacements, inter-story drift, and the probability of collapse using fragility analysis have been investigated through the structures equipped with and without TMD. The results appraise the effect of TMD and compare the seismic responses of earthquake frequency contents and the vibration control system of the inelastic building frames.


2005 ◽  
Vol 128 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh

Whenever a tuned-mass damper is attached to a primary system, motion of the absorber body in more than one degree of freedom (DOF) relative to the primary system can be used to attenuate vibration of the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to suppress single-mode vibration of a primary system. We cast the problem of optimization of the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to zero. With properly chosen connection locations, the two-DOF absorber achieves better vibration suppression than two separate absorbers of optimized mass distribution. A two-DOF absorber with a negative damper in one of its two connections to the primary system yields significantly better performance than absorbers with only positive dampers.


2016 ◽  
Vol 20 (9) ◽  
pp. 1375-1389 ◽  
Author(s):  
Mohammad Sabbir Rahman ◽  
Md Kamrul Hassan ◽  
Seongkyu Chang ◽  
Dookie Kim

The primary objective of this research is to find the effectiveness of an adaptive multiple tuned mass damper distributed along with the story height to control the seismic response of the structure. The seismic performance of a 10-story building was investigated, which proved the efficiency of the adaptive multiple tuned mass damper. Structures with single tuned mass damper and multiple tuned mass dampers were also modeled considering the location of the dampers at the top of the structure, whereas adaptive multiple tuned mass damper of the structure was modeled based on the story height. Selection of the location of the adaptive multiple tuned mass damper along with the story height was dominated by the modal parameters. Participation of modal mass directly controlled the number of the modes to be considered. To set the stage, a comparative study on the displacements and modal energies of the structures under the El-Centro, California, and North-Ridge earthquakes was conducted with and without various types of tuned mass dampers. The result shows a significant capability of the proposed adaptive multiple tuned mass damper as an alternative tool to reduce the earthquake responses of multi-story buildings.


Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh

Whenever a tuned-mass damper is attached to a primary system, there is potential for utilization of motion of the absorber body in more than one degree of freedom relative to the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to a single natural frequency of the primary system. We cast the problem of optimizing the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem, and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to be zero. With properly chosen connection locations, the two-DOF absorber can achieve better vibration suppression than two separate absorbers of optimized mass distribution. We also find that a two-DOF absorber with negative dampers in some of the connections to the primary system can obtain much better performance than absorbers with only positive dampers.


Author(s):  
Mohammad Shamim Miah ◽  
Md. Jihad Miah ◽  
Md. Ashik Hossain

The structures are prone to dynamic loads such as earthquake as they often generate uncomfortable movement into existing structures. In order to reduce extreme vibration generated by dynamic or operational loads passive, active or hybrid controlling devices are used. And the advantages of passive systems are well accepted due to their inexpensiveness and simplicity. This study investigates the performance of a newly developed uniaxial tuned mass damper (TMD). The novelty of the developed device is that the properties of the damper are adjustable based on the structural requirements. And most importantly, another key design criterion is to make a low-cost affordable device. To do this end, a toy two degree of freedom (2-DOF) system is considered and the experiments are conducted. The experimental tests and numerical simulations are carried out on the structure without and with TMD along with extra masses of 25 kg, 30 kg and 35 kg on the floors to observe the effect of floor mass changes. The scaled El Centro 1940 earthquake data is used as input excitation. In order to determine the optimal performance of the damper, it is tuned to modal mass of 0% (i.e., without TMD), 5%, 7.5%, 10%, 12.5%, and 17.5%. The experimental results have shown that the structure without TMD has pronounced vibration (i.e., displacement) as compared to the structure with TMD. As the percentage of modal mass increases, the vibration of the structure decreases. It is observed that up to 12.5% of modal mass for both 20 and 25 sec excitation duration could be the optimum amount that minimizes the vibration of the structure. The overall performance of this device is capable of reducing vibration in a reasonable manner and has the possibility to use it for the real engineering application.


2020 ◽  
Vol 22 (4) ◽  
pp. 983-990
Author(s):  
Konrad Mnich

AbstractIn this work we analyze the behavior of a nonlinear dynamical system using a probabilistic approach. We focus on the coexistence of solutions and we check how the changes in the parameters of excitation influence the dynamics of the system. For the demonstration we use the Duffing oscillator with the tuned mass absorber. We mention the numerous attractors present in such a system and describe how they were found with the method based on the basin stability concept.


Author(s):  
Marcelio Ronnie Dantas de Sá ◽  
Armando Wilmans Nunes da Fonseca Júnior ◽  
Yuri Moraes ◽  
Antonio Almeida Silva

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.


Sign in / Sign up

Export Citation Format

Share Document