Study on Machining Vibration Suppression with Multiple Tuned Mass Dampers: Vibration Control for Long Fin Machining

2017 ◽  
Vol 11 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Ippei Kono ◽  
◽  
Takayuki Miyamoto ◽  
Koji Utsumi ◽  
Kenji Nishikawa ◽  
...  
Keyword(s):  
Vibration Control ◽  
Vibration Suppression ◽  
Dynamic Stiffness ◽  
System Model ◽  
End Mill ◽  
Lumped Mass ◽  
Tuned Mass Dampers ◽  
Machining Test ◽  
Low Stiffness ◽  
Multiple Tuned Mass Dampers

This study aims to suppress vibration during the machining of long and thin fin parts. Typically, fin parts have low stiffness because fixing the fin is impeded by a end-mill, machine tool or other fins. In this study, multiple tuned mass dampers (TMDs) with the same characteristics were applied to the machining of a fin part measuring 18 mm × 180 mm × 2600 mm. The characteristics of the TMDs were optimized by calculation using a lumped-mass-points system model of the fin part. Then, an impact hammer test and a machining test were conducted on the actual fin part. The dynamic stiffness of the fin part was improved by up to 14 times by using five TMDs, and the amplitude of vibration during machining was decreased by more than 90%.

scholarly journals Robust Optimum Design of Multiple Tuned Mass Dampers for Vibration Control in Buildings Subjected to Seismic Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Luciara Silva Vellar ◽  
Sergio Pastor Ontiveros-Pérez ◽  
Letícia Fleck Fadel Miguel ◽  
Leandro Fleck Fadel Miguel
Keyword(s):  
Vibration Control ◽  
Structural Parameters ◽  
Simultaneous Optimization ◽  
Tuned Mass Dampers ◽  
Structural Dynamic ◽  
Energy Devices ◽  
Promising Tool ◽  
Optimization Methodology ◽  
Robust Optimum Design ◽  
Multiple Tuned Mass Dampers

Passive energy devices are well known due to their performance for vibration control in buildings subjected to dynamic excitations. Tuned mass damper (TMD) is one of the oldest passive devices, and it has been very much used for vibration control in buildings around the world. However, the best parameters in terms of stiffness and damping and the best position of the TMD to be installed in the structure are an area that has been studied in recent years, seeking optimal designs of such device for attenuation of structural dynamic response. Thus, in this work, a new methodology for simultaneous optimization of parameters and positions of multiple tuned mass dampers (MTMDs) in buildings subjected to earthquakes is proposed. It is important to highlight that the proposed optimization methodology considers uncertainties present in the structural parameters, in the dynamic load, and also in the MTMD design with the aim of obtaining a robust design; that is, a MTMD design that is not sensitive to the variations of the parameters involved in the dynamic behavior of the structure. For illustration purposes, the proposed methodology is applied in a 10-story building, confirming its effectiveness. Thus, it is believed that the proposed methodology can be used as a promising tool for MTMD design.

An improved multi-mode seismic vibration control method using multiple tuned mass dampers

2022 ◽  
pp. 136943322110509
Author(s):  
Xuan Zhang ◽  
Qiang Han ◽  
Kaiming Bi ◽  
Xiuli Du
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Numerical Study ◽  
Ground Motions ◽  
Vibration Modes ◽  
Tuned Mass Dampers ◽  
Location Factor ◽  
Mass Damper ◽  
Multi Mode ◽  
Multiple Tuned Mass Dampers

Multiple vibration modes of an engineering structure might be excited by earthquake ground motions. Multiple tuned mass dampers (MTMDs) are widely used to control these multi-mode vibrations. However, in the commonly used MTMD system, the mass element in each tuned mass damper (TMD) is normally assumed to be the same. To improve the performance of MTMDs for seismic-induced vibration control, non-uniform MTMD masses are adopted in the present study to improve the mass utilization of TMD, and a location factor is proposed to determine the best location of each TMD in the MTMD system. The effectiveness of the proposed method is validated through numerical study. The results show that the proposed method effectively reduces the seismic responses of the structure induced by multiple vibration modes.

Experimental Vibration Control of a Two-Degree of Freedom, State-Switched Absorber System

2002 ◽  
Author(s):  
Mark H. Holdhusen ◽  
Kenneth A. Cunefare
Keyword(s):  
Vibration Control ◽  
Vibration Suppression ◽  
Effective Bandwidth ◽  
Vibration Absorbers ◽  
Lumped Mass ◽  
Tuned Vibration Absorbers ◽  
Resonance Frequencies ◽  
Magneto Rheological ◽  
Theoretical Simulations ◽  
Two Degree Of Freedom

A State-Switched Absorber (SSA) is a device capable of instantaneously changing its stiffness, thus it can switch between resonance frequencies, increasing its effective bandwidth as compared to classical tuned vibration absorbers for vibration control. Previous theoretical simulations show that for a system subjected to a multi-harmonic disturbance, using an appropriate logic for switching states, the SSA reduces vibration more effectively than classical tuned vibration absorbers (TVA). This paper considers the experimental performance of the SSA for vibration suppression of an elastically mounted lumped mass base. State switching is achieved using magneto-rheological fluid to connect or disconnect a coil spring in parallel with other coil springs. The stiffness state is controlled by applying or removing a magnetic field across of the MR fluid. Experiments were performed over a range of forcing and tuning frequencies. The SSA system, optimally tuned, outperformed the optimal classical TVA system for all combinations of forcing frequencies.

Optimum placement and design of multiple tuned mass dampers for vibration control of asymmetric buildings

2021 ◽  
pp. 107754632110381
Author(s):  
Jer-Fu Wang ◽  
Ging-Long Lin ◽  
Chi-Chang Lin ◽  
Jie-Yong Jian
Keyword(s):  
Vibration Control ◽  
Coupling Effect ◽  
Design Procedure ◽  
Structural Safety ◽  
Mode Shapes ◽  
Base Shear ◽  
Tuned Mass Dampers ◽  
Asymmetric Buildings ◽  
Moving Direction ◽  
Multiple Tuned Mass Dampers

This study proposed a design procedure to determine the optimal location, moving direction, and system parameters of multiple tuned mass dampers systematically for vibration control of asymmetric buildings under dynamic loadings such as earthquake or wind excitations. A piece of computer software was developed as a postprocessor of any commercial structural analysis programs, such as ETABS, SAP2000, and so on. First, the modal parameters of target building structure were extracted from its finite element model. The optimum location and moving direction of the multiple tuned mass dampers system are determined based on the controlled mode shapes and both modal participating mass ratio and modal direction factor. Then, the optimal parameters of the multiple tuned mass dampers system were calculated by minimizing the mean square modal displacement response ratio of the controlled mode for the target building with and without multiple tuned mass dampers system. To evaluate control effectiveness, the responses of the building with and without multiple tuned mass dampers system were compared in both frequency and time domains. The analysis results from a 5-story building with different torsion-coupling degrees and a 46-story real building show that the proposed multiple tuned mass dampers system is quite effective in mitigating excessive floor vibration, base shear, and elapsed time of vibration due to earthquake excitations to enhance both structural safety and resident comfort. It is also concluded that the torsion-coupling effect should be considered in determining the optimum planar location of multiple tuned mass dampers system which is equivalent to mass increase of the multiple tuned mass dampers system and thus improves the control efficacy for asymmetric buildings.

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