Inverted Pendulum Mass Damper for Low-Frequency Building Oscillation
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Solution Overview
Problem
Conventional tuned mass dampers for tall structures face limitations in achieving low-frequency vibration control due to the required length of pendulums, which often exceeds typical story heights, and are not compact or maintenance-free, limiting their effectiveness and space efficiency.
Innovation Solution
A suspended inverted pendulum mass damper with a balanced mass supported by a first spring system and a floating base unit, allowing horizontal movement and adjustable spring configuration to extend the effective pendulum length, reducing the angle of rotation and enabling efficient low-frequency vibration control with minimal maintenance and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional simple gravity pendulum is used as tuned mass damper, then the pendulum can damp vibrations, 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 rather than suspending it from above. This inverted pendulum design changes the relationship between pendulum length and natural frequency, allowing low-frequency vibration control without requiring excessively long pendulums that would exceed typical story heights in tall buildings.
Solution Approach 2:
The invention changes the fundamental parameter relationship by using an inverted pendulum configuration where the natural frequency is no longer directly proportional to the square root of length as in conventional pendulums. This parameter change enables the system to achieve low-frequency tuning (0.05-0.3 Hz) with compact dimensions suitable for modern high-rise buildings.
2Reliability
If a spherical Tuned Mass Damper weighing approximately 730 tons is installed in Taipei 101, then low frequency vibrations can be damped, but the device occupies significant space from the 87th to the 91st floor
Solution Approach 1:
By inverting the pendulum configuration and using a compact supporting structure rather than a long suspended cable, the device achieves low-frequency vibration control in a much more space-efficient manner, requiring minimal vertical space compared to the Taipei 101 TMD that occupied five floors.
Solution Approach 2:
The invention transitions from the conventional vertical suspension approach to a compact supporting structure that may utilize horizontal or multi-dimensional arrangements, fundamentally changing the spatial footprint requirements for low-frequency tuned mass dampers in tall buildings.
3Strength
If the carrying part extends above the mass to support it, then the mass can be supported, but the design does not allow horizontal movement of the base unit
Solution Approach 1:
The patent inverts the support configuration by placing the carrying part below the mass rather than above it. This inversion enables the base unit to move horizontally while supporting the mass, providing the versatility needed for effective vibration control in various building conditions.
Solution Approach 2:
The supporting structure is designed to be dynamic rather than fixed, allowing the base unit to move horizontally in response to building vibrations. This dynamic capability enhances the adaptability of the system to different vibration patterns and building movements.
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 occupancy while effectively damping low-frequency vibrations in tall structures, allowing for versatile application across various frequencies and structural types, enhancing user comfort and safety without exceeding structural limits.
Implementation Method 1
A pendulum mass damper for damping oscillations of a structure comprises a mass (1) balanced by a first spring system (2a, 2b, 2c)
Implementation Method 2
the unit (5) is floating i.e. the unit (5) can move either horizontally or both horizontally and vertically
Implementation Method 3
A suspended inverted pendulum mass damper with a balanced mass supported by a first spring system and a floating base unit, allowing horizontal movement
Implementation Method 4
A pendulum mass damper for damping oscillations of a structure
Implementation Method 5
capable of damping a dynamic response of a variety of structural systems vibrating horizontally at low frequencies
Data Source
AI summary
A pendulum mass damper is directed to damping oscillation of tall buildings, towers or similar flexible structures requiring a low frequency tuned mass damper (TMD) for reducing a e.g. wind or earthquake induced displacement response of the structure. A mass (1) is 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 in the vertical direction extends between the mass and a position (C) below the mass, i.e. the weight of the mass is carried or supported from or at a point or level below the mass, wherein the mass 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 which unit is floating i.e. the unit can move either horizontally or both horizontally and vertically.