Tuned liquid column damper for structural control

Summary.

Tuned liquid column dampers (TLCDs) are energy dissipating substructures, which can be used to improve the dynamics of structures. The basic operating principle is an energy transfer from the vibrating host structure to the TLCD. A TLCD consists of a rigid piping system which is integrated in a structure and partially filled with liquid, preferably water. Its dynamics can be derived using the extended instationary Bernoulli’s equation for moving reference systems. Although both the construction and working principle of TLCDs differ from tuned mass dampers (TMDs), an analogy between the different types of absorber is given. Extending the passive TLCD by an actively controlled air-spring setup, and applying a suitable control strategy results in a novel hybrid active damper which combines both, the advantages of active control devices, and the salient features of TLCD, e.g., cheap and easy implementation into civil engineering structures, simple modification of the natural frequency and damping properties, little maintenance costs, a performance comparable to TMD as well as little additional weight if the TLCD is used as water reservoir for fire fighting. In numerical simulations of dynamically excited structures the proposed TLCD shows a considerable vibration reduction for wind and earthquake loading.