Instantaneous Phase Detection for Performance Verification of Tuned Mass Dampers

2015 ◽  
Author(s):  
Ging-Long Lin ◽  
Chi-Chang Lin
Keyword(s):  
Power Flow ◽  
Phase Detection ◽  
Control Performance ◽  
Tuned Mass Dampers ◽  
Civil Structures ◽  
Theoretical Derivation ◽  
Control Effectiveness ◽  
Instantaneous Phase ◽  
Mass Damper ◽  
The Right

Vibration control using tuned mass damper (TMD) for civil structures has been widely accepted and used in buildings and bridges. However, the TMD provides a frequency-dependent damping for the primary structure. The control effectiveness of TMD will vary with the frequency content of the excitation. A method to verify the control performance of TMD is lack in the literatures. In this study, two simple indicators were developed to judge the TMD control performance based on the theoretical derivation, which indicates the maximum power flow is occurred when the TMD stroke lags the structural displacement by ninety degree. The proposed indicators were verified by numerical simulation. The results show the proposed indicators can judge the effective of TMD correctly. In addition, the waveform of the instantaneous phase is helpful to adjust the TMD stiffness to the right value.

Analytical analysis for the design of nonlinear tuned mass damper

2020 ◽  
Vol 26 (9-10) ◽  
pp. 646-658
Author(s):  
Lu-yu Li ◽  
Tianjiao Zhang
Keyword(s):  
Passive Control ◽  
Design Method ◽  
Tuned Mass Damper ◽  
Control Device ◽  
Control Performance ◽  
Tuned Mass Dampers ◽  
Mass Damper ◽  
Practical Engineering ◽  
Optimum Formula ◽  
Nonlinear Tuned Mass Damper

A tuned mass damper is a passive control device that has been widely used in aerospace, mechanical, and civil engineering as well as many other fields. Tuned mass dampers have been studied and improved over the course of many years. In practical engineering applications, a tuned mass damper inevitably produces some nonlinear characteristics due to the large displacement and the use of the limiting devices, but this nonlinearity is often neglected. The simulation results in this study confirm that neglecting the nonlinearity in the design process can produce adverse effects on the control performance. This paper takes into account the nonlinearity of the tuned mass damper produced in the process of vibration and deduces an optimum formula for the frequency of a tuned mass damper by the complexification averaging method and multiscale method. Based on this formula, a modified design method for the frequency of a tuned mass damper is presented. The numerical results show that the nonlinear tuned mass damper after modification is better than a linear tuned mass damper in terms of control performance.

Controllability Analysis of Flexible Variable Sweep Control Wing

2012 ◽  
Vol 542-543 ◽  
pp. 873-877
Author(s):  
Lai Bin Xu ◽  
Shu Xing Yang ◽  
Bo Mo
Keyword(s):  
Control Surface ◽  
Control Performance ◽  
Swept Wing ◽  
Sweep Angle ◽  
Low Speed ◽  
Control Effectiveness ◽  
Control Moment ◽  
Speed Range ◽  
Effective Angle ◽  
The Right

Variable Sweep Control Wing (VSCW) was introduced to generate the rolling control moment with the sweep angle differences between the left and the right wings. Influence flexible matrixes were generated to obtain the deflection of the effective angle of attack (AOA) of the flexible swept wing. Comparison between aileron control surface and VSCW shows that VSCW can get benefit from wing flexibility, which degrades the control effectiveness of the traditional aileron. The main advantage and difference from the traditional aircraft is that VSCW has higher control effectiveness and can prevent control reversal especially at high flight speed range; and at low speed, with an AOA variation device VSCW can get similar rolling control performance compared with traditional aileron control surface.

Vibration Control Performance of Damping Coupled Tuned Mass Dampers

2004 ◽  
Author(s):  
Nobuo Masaki ◽  
Hisashi Hirata
Keyword(s):  
Vibration Control ◽  
Natural Frequency ◽  
Tuned Mass Damper ◽  
Control Performance ◽  
Tuned Mass Dampers ◽  
Mass Unit ◽  
Optimal Value ◽  
Mass Damper ◽  
Rubber Bearings ◽  
Prefabricated Houses

Recently tuned mass dampers have been installed on three-story prefabricated houses for reducing of traffic-induced vibration and improving living comfort. This tuned mass damper consists of a mass unit, spring units and laminated rubber bearings. The mass is supported by four laminated rubber bearings, and spring units are used for adjusting the natural frequency of the tuned mass damper to the optimal value. Vibration control performance of this type of tuned mass dampers is deteriorated when the natural frequency of the house is changed. To solve this problem, the authors have developed a damping coupled tuned mass damper. In this type of tuned mass damper, two mass units having slightly different natural frequencies are coupled by using a damping unit. In this paper, mechanism and vibration control performance of the damping coupled tuned mass damper are described.

scholarly journals Seismic Vibration Mitigation of a Cable-Stayed Bridge with Asymmetric Pounding Tuned Mass Damper

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Peng Zhang ◽  
Jie Tan ◽  
Haitao Liu ◽  
Gang Yang ◽  
Chunyi Cui
Keyword(s):  
Numerical Model ◽  
Vibration Control ◽  
Time History ◽  
Tuned Mass Damper ◽  
Force Model ◽  
Control Effectiveness ◽  
Cable Stayed Bridge ◽  
Mass Damper ◽  
The Right ◽  
Side Gap

In order to mitigate the seismic response of a cable-stayed bridge, a new type damping device named asymmetric pounding tuned mass damper (APTMD) is developed in this paper on the basis of the traditional symmetric pounding tuned mass damper. The novel APTMD has three parameters to be determined: the left-side gap, the right-side gap, and the frequency ratio. A numerical model of the APTMD damping system is established with consideration of both the computational efficiency and accuracy to enable the parametric optimization of the damper. The numerical model is based on a simplified model of the cable-stayed bridge and a nonlinear pounding force model. The genetic algorithm is utilized for the optimization of the damper. Afterwards, the cable-stayed bridge is subjected to 20 recorded ground motions to evaluate the vibration control effectiveness of the APTMD. Four systems are considered: (1) without dampers; (2) with a TMD; (3) with a PTMD; and (4) with an APTMD. Time history analysis reveals the following: (1) those dampers can all effectively suppress the vibration of the bridge and (2) the vibration control effectiveness of the APTMD is slightly better than the TMD and the PTMD.

Effectiveness of Location and Number of Multiple Tuned Mass Damper for Seismic Structures

2020 ◽  
Vol 9 (6) ◽  
pp. 780-783
Keyword(s):  
Seismic Response ◽  
Software Tool ◽  
Tuned Mass Damper ◽  
Structure Study ◽  
Structural Performance ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Maximum Reduction ◽  
Mass Damper ◽  
Earthquake Data

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.

A phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kothari ◽  
Bhavesh R. Bhalja ◽  
Vivek Pandya ◽  
Pushkar Tripathi ◽  
Soumitri Jena
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Detection Algorithm ◽  
Current Transformer ◽  
Operating Conditions ◽  
Fault Classification ◽  
Phase Detection ◽  
Parallel Transmission ◽  
Classification Technique ◽  
Computational Requirement

AbstractThis paper presents a phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines. Detection and classification of faulty phase(s) have been carried out by deriving indices from the change in phasor values of current with a distance of one cycle. The derived indices have zero values during normal operating conditions whereas the index corresponding to the faulty phase exceeds the pre-defined threshold in case of occurrence of a fault. A separate ground detection algorithm has been utilized for the identification of involvement of ground in a faulty situation. The performance of the proposed technique has been evaluated for intra-circuit, inter-circuit and simultaneous faults with wide variations in system and fault conditions. The suggested technique has been evaluated for over 23,000 diversified simulated fault cases as well as 14 recorded real fault events. The performance of the proposed technique remains consistent under Current Transformer (CT) saturation as well as different amount and direction of power flow. Moreover, suitability to different power system network has also been studied. Also, faults having fault current less than pre-fault conditions have been detected accurately. The results obtained suggest that it is able to detect faulty phases as well as classify faults within quarter-cycle from the inception of fault with impeccable accuracy. Besides, as modern digital relays have been already equipped with phasor computation facility, phasor-based technique can be easily incorporated with relative ease. At last, a comparative evaluation suggests its superiority in terms of fault classification accuracy, fault detection time, diversify fault scenarios and computational requirement among other existing techniques.

Adaptive multiple tuned mass dampers based on modal parameters for earthquake response reduction in multi-story buildings

2016 ◽  
Vol 20 (9) ◽  
pp. 1375-1389 ◽  
Author(s):  
Mohammad Sabbir Rahman ◽  
Md Kamrul Hassan ◽  
Seongkyu Chang ◽  
Dookie Kim
Keyword(s):  
Tuned Mass Damper ◽  
Primary Objective ◽  
Modal Parameters ◽  
Earthquake Response ◽  
Tuned Mass Dampers ◽  
Mass Damper ◽  
Modal Mass ◽  
Story Building ◽  
Selection Of ◽  
Multiple Tuned Mass Dampers

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.

Back-iron design-based electromagnetic regenerative tuned mass damper

2020 ◽  
Vol 234 (3) ◽  
pp. 607-622
Author(s):  
Semen Kopylov ◽  
Zhaobo Chen ◽  
Mohamed AA Abdelkareem
Keyword(s):  
Root Mean Square ◽  
Tuned Mass Damper ◽  
Harmonic Excitation ◽  
Experimental Results ◽  
Mean Square ◽  
Tuned Mass Dampers ◽  
Practical Applications ◽  
Mass Damper ◽  
Compact Dimension ◽  
Regenerative Power

Implementation of tuned mass dampers is the commonly used approach to avoid excessive vibrations in civil engineering. However, due to the absence of the compact dimension, there are still no practical applications of the tuned mass dampers in automotive industry. Meanwhile, recent investigations showed the benefit of utilizing a tuned mass damper in a vehicle suspension in terms of driving comfort and road holding. Thus, the current investigation aimed to explore a novel compact dimension tuned mass damper, which can provide both sufficient vibration mitigation and energy harvesting. This paper presents a prototype of a back-iron-based design of an electromagnetic regenerative tuned mass damper. The mathematical model of the tuned mass damper system was developed and has been validated by the experimental results of the tuned mass damper prototype implemented in a protected mass test-bench. The indicated results concluded that the attenuation performance dramatically deteriorated under random excitations and a reduction in the root-mean-square acceleration of 18% is concluded compared to the case with undamped tuned mass damper. Under harmonic excitations, the designed tuned mass damper prototype is able to reduce the peak acceleration value of the protected structure by 79%. According to the experimental results, the designed tuned mass damper prototype revealed a peak regenerative power of 0.76 W under a harmonic excitation of 8.1 Hz frequency [Formula: see text]m amplitude. Given the simulated random road profiles from C to E, the back-iron electromagnetic tuned mass damper indicated that root-mean-square harvested power from 0.6 to 6.4 W, respectively.

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