MAURER Tuned Mass and Viscous Dampers
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Technical Information /l\ MAURER MAURER Tuned Mass Dampers Tl 001 EN/2016-03

MAURER Tuned Mass DampersTuned mass damper types Problem description Civil engineering structures may be prone to large amplitude vibrations due to wind and earthquake loading mechanisms because of their slenderness and low inherent damping ratio of approx. 1% (Fig. 1). Without additional damping measures the following problems may arise: ■ Wind loading mechanisms may evoke resonant and therefore large amplitude oscillations in high rise buildings which dramatically reduce the comfort (seasickness) and therefore limit the use of the building. ■ Free vibrations of tall buildings after...

MAURER Tuned Mass Dampers MAURER General advantages of MAURER TMDs ■ The different mass damper types guarantee the best solution to the vibration problem. ■ Model-based optimal design of all mass damper types by MAURER as service. ■ Vibration measurement on the structure by MAURER. ■ Quality control by measurement of TMD properties in the workshop and installed in the structure. ■ MAURER TMDs are robust, maintenance-free and long-living (>20 years) due to their optimal design, precise manufacturing process and quality controls. Specific benefits of MAURER TMD types ■ standardTMD: cost...

MAURER Tuned Mass Dampers max 1 Optimal design Input data The optimal designs of the natural frequency f2 and damping ratio £2 of TMDs for minimum structural displacement amplitude mir^X-i) and minimum structural acceleration amplitude minfX.,), respectively, require the knowledge of the following data (Fig. 4): ■ the target structural eigenfrequency f-\ including the maximum variation ±Af| /f-| due to the impacts of changing ambient temperature and life loads, ■ the associated modal mass m1, ■ the maximum acceptable displacement amplitude X and acceleration amplitude Xi’ax of the...

MAURER Tuned Mass Dampers MAURER Passive TMDs The natural frequency f2 and damping ratio £2 of the passive TMD types standardTMD, foldedTMD and compactTMD for minimum structural displacement amplitude X-, are given by Den Hartog's formulae [1] c - f1 If the acceleration amplitude X-| of the structure is to be minimized, f2 and £2 must be designed as follows The spring stiffness and the viscous damper coefficient of the oil damper of the standardTMD are obtained from (2, 3) for min(X1) and from (4, 5) for minO^) as follows Figs. 5 and 6 depict the vibration reductions of the primary...

MAURER Tuned Mass Dampers C2-1 Adaptive TMDs Frequency tuning in real-time The controlledTMD is a MAURER in-house production [2-5]. Its controlled frequency ^-controlledis adjusted in realtime to the actual frequency fp of vibration according to the principle of the undamped dynamic vibration absorber (Frahm, [6]) ^2-controlled= ^p (8) where fp may represent a forced frequency or an eigenfrequency of the structure including the variation range ±Af-| /f-| . Due to the design of the passive spring stiffness k2 =m2(27T f-i)2 the actuator must emulate only the differential stiffness (Fig....

MAURER Tuned Mass Dampers MAURER Key features ■ Improved vibration reduction at nominal mass ratio: - vibration reduction enhanced by up to 60% compared to the passive TMD at worst case excitation due to wind or earthquake loadings (Fig. 9) without augmented damper relative motion amplitude (Fig. 12) - maximum comfort in buildings due to improved vibration reduction of up to 80% compared to passive TMD at medium to small and therefore frequently occurring wind or earthquake loadings (<50% worst case, Fig. 10) ■ Same vibration reduction as with passive TMD: reduction of tuned mass to 75% to...

MAURER Tuned Mass Dampers MAURER References SOCflR Tower in Baku, Azerbaijan ■ The pendulum lengths of the 2-dimensional foldedTMD are adjusted for maximum vibration reduction of the first eigenmodes in both main directions at 0.22 Hz and 0.32 Hz (Fig. 15). ■ The total height of the folded pendulum including the steel frame construction, cable clamping devices and lead rubber bearings could be reduced from approx. 11m of the conventional pendulum TMD to approx. 7 m of the foldedTMD (Fig. 16). ■ The damper mass of 450 tons of the foldedTMD corresponds to the mass ratio of 4.5%. ■ The steel...

MAURER Tuned Mass Dampers MAURER Alphabetic Tower in Batumi, Georgia ■ The standardTMD in pendulum form (Fig. 17) is optimally tuned to the eigenfrequency of 0.498 Hz in both main directions of the Alphabetic Tower in Batumi (Fig. 18). ■ The damper mass of 62.85 tons of the standardTMD corresponds to the mass ratio of 3.50%. ■ The joints and lengths of the pendulum rods and the cylindrical oil dampers are designed for the maximum damper relative motion amplitude of ±0.24 m. ■ The standardTMD of the Alphabetic Tower in Batumi is in operation since December 2011.

MAURER Tuned Mass Dampers MAURER Danube City Tower in Vienna, Austria ■ The controlledTMD of the Danube City Tower generates optimal frequency and damping tunings in real-time of the first bending mode within the frequency range of 0.17 Hz to 0.21 Hz [A, 5, 7] which was experimentally verified by HIL tests (Fig. 19). ■ The control force range of both real-time controlled semi-active dampers is given by the residual force of approx. 3 kN and the maximum force of approx. 90 kN. ■ The tuned mass of 300 tons (not delivered by MAURER) corresponds to the mass ratio of 0.75%. ■ The adaptive...

MAURER Tuned Mass Dampers MAURER Volgograd Bridge, Russia ■ Field measurements and wind channel tests demonstrated that the first three vertical bending modes at 0.45 Hz, 0.56 Hz and 0.68 Hz are to be mitigated. ■ MAURER solved this problem by three groups of controlledTMDs in bridge fields 3, 7 and 8 as follows: - the natural frequencies of the passive mass spring packets are optimally tuned to the eigenfrequencies of the three vertical bending modes and - the controlled frequencies of all controlledTMDs are adjusted to the actual frequency of vibration which yields the same vibration...