S-TLCD: Semi-active Tuned Liquid Column Damper

Project title: Semi-active tuned liquid column damper for civil engineering structures
Funding: BMBF – Bundesministerium für Bildung und Forschung
Grant number: 03VP04680
Project agency: Projekt Träger Jülich

VDI/VDE Innovation + Technologie GmbH

Project partner: IRT – Institut für Regelungstechnik, RWTH Aachen University
Project coordinator: Dr.-Ing. O. Altay

+49 241 80 25863


Project period: 12/2018-11/2021

Project outlines

Civil engineering structures must resist natural and anthropogenic influences during their entire service life. In the most unfavourable case, the loading can exceed the structural performance, which can even lead to a collapse of the structure. In Germany, especially wind loads are decisive for the safety of high-rise structures, such as high-rise buildings, chimneys and wind energy turbines. For instance, due to dynamic loading the operation time for wind energy turbines are usually limited for only 20 years, which, from economic point of view, is not sufficient. Another challenge for the society and economy are road bridges. Solely, within Germany, the highway network consists 38,000 road bridges. One spectacular example is the highway bridge A1 – Rheinbrücke in Leverkusen, which has been closed since 2012 for lorries because of the poor condition of the structure.

To improve the dynamic resistance of civil engineering structures, RWTH Aachen University developed the Semi-active Tuned Liquid Column Damper (S-TLCD). The damper system, similar to the shock absorbers used in the automotive industry, can dissipate the vibration energy. The high-rise building in Taipei, as well as the TV-Tower of Berlin, are both equipped with a pendulum damper systems. Due to altering structural parameters and changing load situations, these passive damping measures show a loss of effectiveness during the service lifetime of the building. S-TLCD has the ability to adapt to these changes by adjusting its parameters automatically and therefore, can reach a significantly higher stability and efficiency compared to other so far developed measures.

S-TLCD is patented by RWTH Aachen University and a downscale model was successfully tested under laboratory conditions. The goal of this project is to validate the functionality of a real-size S-TLCD under real-world conditions using a reference structure, which belongs to the testing facilities of the RWTH Aachen University.

System sketch of the semi-active tuned liquid column damper (S-TLCD)

Working schedule:

For potential users, the upscaling and the implementation of S-TLCD on an existing structure is financially a high risk. To minimize this venture and to increase the acceptance, further investigations are necessary. The functionality of the damper must be proved under real-world conditions considering scaling effects and weather. To reach this project goal five work packages are defined. The first package comprises the preparation of the reference structure. In this context, the structural parameters and load situations will be determined by in-situ measurements. In the second work package an S-TLCD damping system, serving as a demonstrator, will be designed. This S-TLCD will be adjusted to the referencing structure based on the identified structural parameters. Furthermore, the mechanical components of the damper will be manufactured in the same work package. The third package deals with the development of control algorithms for the identification and tuning of the optimal damping parameters. The fourth work package comprises the installation of the demonstrator, as well as the relating sensors and actuators on the reference structure. In the last work package, the performance validation of the damping system will be carried out by measuring the dynamic response of  the reference structure. For this goal, investigations will conducted under specified load scenarios. The investigations consist of three phases. The first phase involves the simulation of several load situations. The second phase investigates the effects of altering structural parameters. The long-term behavior of the damper will be examined in the third and last phase.

In order to present the outputs, an online-documentation platform will be developed. For this purpose, the data of the sensors will be assembled and displayed graphically. The reference structure and the damping system will be recorded. Furthermore, for potential users, measurements initialized by remote control will be enabled in order to demonstrate the effectivity of the damping system via internet.