A preliminary design method for tuned liquid dampers conforming to space restrictions

The building floor plan may place restrictions on the shape of a tuned liquid damper (TLD) tank, forcing a tank of complex geometry to be used. The behavior of these types of TLDs is not well understood, and a design procedure for this type of TLD is unavailable.Obtaining suitable TLD dimensions and damping screen properties is paramount to TLD efficiency. This study develops a preliminary design procedure for a TLD of complex tank geometry coupled to a 1D structure. First, a linearized equivalent mechanical model representing the fluid is coupled to a linear 1D structure to predict the structure-TLD interaction. Since the structure is 1D, the mechanical model properties are transformed to be aligned with the structural direction of motion. Structure-TLD system tests are conducted to show that the transformed TLD properties can be used to model the system.A design methodology is presented which enables a TLD tank to be designed to conform to space restrictions. To do this, the transformed TLD properties are related to the tank shape using normalized charts. The charts enable a designer to rapidly match transformed TLD properties to a specific tank shape. A tank shape that simultaneously satisfies the geometric restrictions, structure-TLD mass ratio, and natural frequency can be identified from a single chart. Subsequently, charts are used to identify the proper fluid depth and damping screen properties. An example is used to demonstrate the design method, and the resultant TLD’s performance is found to meet the design requirements using the mechanical model.