Inverted Pendulum Mass Damper for Low-Frequency Building Oscillations
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Solution Overview
Problem
Conventional pendulum mass dampers face limitations in achieving low-frequency vibration control due to the requirement for extended lengths, which can exceed typical story heights in tall structures, and are often bulky, requiring significant space and maintenance.
Innovation Solution
A compact, maintenance-free pendulum mass damper with a suspended inverted design, utilizing a spring system to balance the mass and extend the effective pendulum length, allowing the point of rotation to be below the damper application, thereby reducing the angle of rotation and enhancing stability, while enabling low-frequency vibration control with minimal vertical space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pendulum is used as tuned mass damper, then the natural frequency can be adjusted, but the required length L becomes greater than a typical story height for low frequency applications
Solution Approach 1:
The patent inverts the conventional pendulum configuration by supporting the mass from below instead of suspending it from above. This inversion allows the effective pendulum length to be extended downward, achieving low natural frequencies without requiring excessive vertical space above the mass. The carrying part extends between the mass and a position below it, creating an inverted pendulum mechanism that resolves the space-length contradiction.
Solution Approach 2:
The patent transitions from a conventional upward-suspended pendulum to an inverted downward-supported configuration. By changing the dimensional orientation of the support system (from above to below), the effective pendulum length is extended in the vertical dimension without compromising the horizontal vibration control function, thus achieving low frequency tuning within limited story heights.
2Adaptability or versatility
If the pendulum length is increased to achieve lower frequency, then the vibration control range is improved, but the device becomes bulkier and requires more space
Solution Approach 1:
By inverting the pendulum support configuration, the patent extends the effective pendulum length downward through the carrying part rather than upward. This allows the system to achieve low frequency tuning (high adaptability) while keeping the vertical space occupation above the mass minimal, thus reducing the overall device volume requirement.
3Adaptability or versatility
If a spherical mass suspended in cables is used (Taipei 101 type), then multi-directional vibration control is achieved, but the device requires significant space and high maintenance
Solution Approach 1:
The inverted pendulum configuration with mass supported from below simplifies the support structure compared to multi-cable suspension systems. This inversion allows for a more straightforward carrying part design that can still provide multi-directional damping capability while reducing complexity and maintenance requirements.
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 improved stability and reduced space requirements for low-frequency vibration control, allowing the damper to effectively manage structural vibrations in tall structures with reduced maintenance needs.
Implementation Method 1
A pendulum mass damper (1) balanced by a spring system (2a, 2b, 2c) and supported by a carrying part (3, 4) to maintain a vertical position
Implementation Method 2
the weight of the mass (1) is supported from a point or level below the mass (1)
Implementation Method 3
A compact, maintenance-free pendulum mass damper with a suspended inverted design
Implementation Method 4
extend the effective pendulum length, allowing the point of rotation to be below the damper application, thereby reducing the angle of rotation and enhancing stability
Implementation Method 5
pendulum mass damper capable of damping a dynamic response of a variety of structural systems vibrating horizontally at low frequencies
Implementation Method 6
Tuned Mass Damper (TMD), also called a 'harmonic absorber'
Data Source
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AI summary
A tuned pendulum mass damper damping oscillation of tall buildings, towers or similar flexible structures. The pendulum mass damper is directed to applications requiring a low frequency tuned mass damper (TMD) reducing a e.g. wind or earthquake induced displacement response of the structure. A pendulum mass damper for damping oscillations of a structure comprising a mass (1) balanced by a first spring system (2a, 2b, 2c) and supported by a carrying part (4) to maintain a vertical position, the carrying part (4) carrying the mass (1) in the vertical direction extends between the mass (1) and a position (C) below the mass (1), i.e. the weight of the mass (1) is carried or supported from or at a point or level below the mass (1), wherein the mass (1) at the position (C) below the mass is fixed and/or connected to a unit (5) constituting a base of a supporting system for the mass (1) which unit (5) is floating i.e. the unit (5) can move either horizontally or both horizontally and vertically.