Membrane Tuned Liquid Damper for Low-Frequency Building Vibration
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Solution Overview
Problem
Current vibration damping solutions for tall buildings, such as tuned liquid dampers, are either expensive, require extensive customization, or are not adjustable, making them unsuitable for modern structures like slim skyscrapers, and often fail to efficiently dampen wind-induced vibrations due to limitations in frequency tuning and space constraints.
Innovation Solution
A tuned liquid damper with a membrane liquid-gas interface that includes a gas spring system with adjustable parameters, allowing for flexible membrane positioning and gas volume adjustment, which eliminates the contribution of gravity to stiffness, enabling tuning to lower frequencies and efficient vibration damping in slender buildings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a standard TLCD is used, then the damper can be tuned to a particular frequency, but it cannot be tuned to a different frequency without major retrofit and requires large horizontal space
Solution Approach 1:
The patent applies dynamics by making the damper system adjustable and adaptable through movable membranes that can be repositioned to change the liquid column length and gas volume, enabling frequency retuning without major structural retrofit. The system transitions from a fixed configuration to a dynamically adjustable one.
Solution Approach 2:
The patent segments the liquid column into adjustable sections using movable membranes that can be independently positioned. This segmentation allows the liquid column length to be modified in discrete steps, enabling frequency tuning while maintaining a compact vertical configuration.
2Adaptability or versatility
If a spring TLCD is used, then the damper can be tuned to a broader range of frequencies, but the adjustable stiffness can only add to gravity-induced stiffness, preventing tuning to low frequencies of very tall buildings
Solution Approach 1:
The patent extracts the gravity-induced stiffness component by using a vertical configuration where the liquid column oscillates under its own weight without relying on gravity acting on a horizontal span. This removes the minimum stiffness constraint that limits low-frequency tuning in traditional TLCDs.
Solution Approach 2:
The patent transitions from horizontal to vertical orientation, changing the dimensional arrangement of the liquid column. This vertical configuration allows the liquid to oscillate in the vertical dimension under gravity, enabling low-frequency tuning by adjusting the liquid column length without being constrained by horizontal span limitations.
3Reliability
If traditional TLDs are used, then the damper can absorb vibration energy, but it requires extensive customization and increases costs
Solution Approach 1:
The patent creates a universal damper design with standardized components (housing, membranes, liquid column) that can be adapted to different frequency requirements through simple membrane repositioning rather than custom manufacturing. The same basic structure serves multiple frequency tuning needs.
Solution Approach 2:
The patent implements dynamic adjustability through movable membranes that allow the system to be reconfigured for different frequencies after installation, eliminating the need for extensive customization and enabling the same device to serve multiple building frequency requirements.
4Reliability
If solid mass dampers are used, then the damper can reduce wind-induced vibrations, but it is expensive, heavy, and reduces leasable floor space
Solution Approach 1:
The patent uses hydraulics by employing a liquid column (water) as the oscillating mass instead of solid counterweights. The liquid provides the necessary mass for vibration counteraction while being contained in a compact vertical tank, significantly reducing the weight compared to solid mass dampers of equivalent effectiveness.
Solution Approach 2:
The patent transitions from horizontal floor-space-consuming solid mass dampers to a vertical liquid column configuration. This dimensional change allows the damper mass to be stacked vertically rather than occupying horizontal floor area, preserving leasable space while maintaining vibration reduction effectiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides efficient vibration damping across a broader frequency range, reduces the need for extensive customization, and allows for easier adjustment, making it suitable for modern structures with limited space, while maintaining low inherent damping and minimal obtrusiveness.
Implementation Method 1
The stiffness of the gas spring depends on the enclosed volume of gas, which can be adjusted with a moveable plug after the damper is installed.
Implementation Method 2
A standard TLCD is a U-shaped tank filled with water and sized such that the water naturally oscillates in the tank at the same frequency as the wind-induced building motion.
Implementation Method 3
a sealed compartment within the first outer housing, defined by the first and second membranes and being at least partially filled with a liquid, which prevents gas flow through the first outer housing from the first end to the second end
Data Source
AI summary
A tuned liquid damper, including a first outer housing having two ends, the first end being open to the atmosphere and the second end being connected by a conduit to a gas-filled second outer housing. The conduit may be adapted to allow gas flow between the second end and the second outer housing. The tuned liquid damper may also include first and second membranes, each attached to the inside of the first outer housing, and a sealed compartment within the first outer housing defined by the first and second membranes. The sealed compartment may be at least partially filled with a liquid, which prevents gas flow through the first outer housing from the first end to the second end.