scholarly journals A Hybrid Tuned Mass Damper for Response Mitigation of Offshore Platforms

2022 ◽  
Author(s):  
Quoc Huong Cao
Keyword(s):  
Vibration Control ◽  
Tuned Mass Damper ◽  
Offshore Platforms ◽  
Structural Stiffness ◽  
Mass Ratio ◽  
Structural Vibrations ◽  
Numerical Computations ◽  
Tuned Liquid Column Damper ◽  
Parametric Investigation ◽  
Mass Damper

Abstract A new hybrid type of the Tuned Mass Damper (HTMD), which consists of a Tuned Liquid Column Damper (TLCD) fixed on the top of a traditional Tuned Mass Damper (TMD), is developed for vibration control of an offshore platform. The results obtained from the parametric investigation show that the mass ratio between TLCD and TMD significantly affects the HTMD's performance. To assess the effectiveness and robustness of HTMD, extensive comparisons are made between an optimized HTMD and an optimum TMD with the same weight as the HTMD. The numerical computations indicate that the proposed HTMD offers a higher level of effectiveness in suppressing structural vibrations compared with a traditional TMD. However, the optimum HTMD is not robust in resisting the variation of the structural stiffness.

scholarly journals Vibration Control of a High-Rise Slender Structure with a Spring Pendulum Pounding Tuned Mass Damper

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 44
Author(s):  
Qi Wang ◽  
Hong-Nan Li ◽  
Peng Zhang
Keyword(s):  
Vibration Control ◽  
Power Transmission ◽  
Tuned Mass Damper ◽  
Width Ratio ◽  
Seismic Action ◽  
Transmission Tower ◽  
Structural Vibrations ◽  
High Rise ◽  
Mass Damper ◽  
Slender Structure

High-rise structures are normally tall and slender with a large height-width ratio. Under the strong seismic action, such a structure may experience violent vibrations and large deformation. In this paper, a spring pendulum pounding tuned mass damper (SPPTMD) system is developed to reduce the seismic response of high-rise structures. This SPPTMD system consists of a barrel limiter with the built-in viscoelastic material and a spring pendulum (SP). This novel type of tuned mass damper (TMD) relies on the internal resonance feature of the spring pendulum and the collision between the added mass and barrel limiter to consume the energy of the main structure. Based on the Hertz-damper model, the motion equation of the structure-SPPTMD system is derived. Furthermore, a power transmission tower is selected to evaluate the vibration reduction performance of the SPPTMD system. Numerical results revealed that the SPPTMD system can effectively reduce structural vibrations; the reduction ratio is greater than that of the spring pendulum. Finally, the influence of the key parameters on the vibration control performance is conducted for future applications.

Tuned Mass Damper for Vibration Control in Steel Jacket Platforms

2008 ◽  
Author(s):  
A. A. Golafshani ◽  
A. Gholizad
Keyword(s):  
Vibration Control ◽  
Fatigue Damage ◽  
Safety Margin ◽  
Tuned Mass Damper ◽  
Offshore Platforms ◽  
Control Mechanisms ◽  
Sea State ◽  
Steel Jacket ◽  
Mass Damper ◽  
Environmental Events

Considering the stress cycles in joints and members due to wave induced forces on offshore platforms, fatigue analysis is therefore one of the most important analyses in offshore platforms design. Most of steel jacket type platforms located in areas with relatively high ratios of operational sea-states to maximum design environmental events; fall in acceptable safety margin in inplace and seismic analyses. But in fatigue analyses they will face critical condition. Therefore it seems that utilizing control mechanisms with the aim of increasing fatigue life in such platforms will be more preferable to merely deck displacement control. Investigation of tuned mass dampers adjustable parameters optimality for vibration control of wave excited structures implies that optimum tuning and damping ratios are strongly dependent to sea-state in addition to system parameters. The efficiency of optimally designed tuned mass damper for fatigue damage mitigation in realistic steel jacket platforms has been evaluated in this study. Full stochastic spectral analysis method has been employed to estimate the maximum fatigue damage as objective function to be minimized. This leads to a min-max problem which has been solved with Micro Genetic Algorithm. Furthermore the efficiency of a variable TMD with different optimum mass for each sea-state has been evaluated in comparison with a TMD with constant parameters.

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.

scholarly journals Analysis study the used of Tuned Mass Damper (TMD) on an existing train bridge due to high speed train with moving mass load approach

2019 ◽  
Vol 258 ◽  
pp. 05005 ◽  
Author(s):  
Wivia Octarena Nugroho ◽  
Dina Rubiana Widarda ◽  
Oryza Herdha Dwyana
Keyword(s):  
High Speed ◽  
Tuned Mass Damper ◽  
Dynamic Responses ◽  
Mass Ratio ◽  
High Speed Train ◽  
Maximum Deformation ◽  
Mass Load ◽  
Mass Damper ◽  
Existing Bridges ◽  
Comfort Criteria

As the need of the train speed increased, the existing bridges need to be evaluated, especially in dynamic responses, which are deformation and acceleration. In this study, Cisomang Bridge is modeled and analyzed due to the high-speed train SJ X2 in varying speeds, 50 km/h, 100 km/h, 150 km/h, and 200 km/h. The used of tuned mass damper also will be varied on its setting and placing. The tuned mass dampers setting be varied based on the first or second natural frequency and the placing of tuned mass damper be varied based on maximum deformation of the first or second mode. Moreover, the tuned mass damper ratio will be varied 1% and 1.6%. For all speed variations, dynamic responses of structure without TMD still fulfil the Indonesian Government Criterion based on PM 60 - 2012 but do not meet requirement of comfort criteria based on DIN-Fachbericht 101. Furthermore, only for the speed train 50km/h dynamic responses of structure fulfil safety criteria based on Eurocode EN 1990:2002, whereas the other speed variations do not meet that requirement. In the use of TMD 1% mass ratio, the structure fulfils the safety criteria for all speed variations. In the use of TMD 1.6% mass ratio, all the structure fulfils the safety and comfort criteria except 100 km/h speed which only fulfils the safety criteria.

Vibration control of flexible structures with an Active Modal Tuned Mass Damper

2011 ◽  
Vol 44 (1) ◽  
pp. 5371-5376 ◽  
Author(s):  
G. Cazzulani ◽  
C. Ghielmetti ◽  
F. Resta ◽  
F. Ripamonti
Keyword(s):  
Vibration Control ◽  
Flexible Structures ◽  
Tuned Mass Damper ◽  
Mass Damper
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