Active Inerter Damper Using Rotational Mass for Building Vibration Control
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Solution Overview
Problem
Large-scale tuned mass dampers (TMDs) occupy excessive space, exert excessive gravity force, and face high friction and inertial forces, limiting their effectiveness in reducing vibrations in large buildings during earthquakes and winds, leading to discomfort for occupants.
Innovation Solution
An active inerter damper system that converts linear motion into rotational motion using a lead screw and rotational mass block, allowing a smaller and lighter mass to generate sufficient inertial force, reducing the need for structural reinforcement and space, and actively controlling the damper force to mitigate dynamic responses without considering friction or structural forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large-scale TMD is used to achieve effective vibration reduction in large buildings, then the damping effect is improved, but the space occupied and structural reinforcement needed increase significantly
Solution Approach 1:
The patent changes the fundamental parameter of mass motion from linear to rotational. By using a rotational mass block instead of a linear moving mass, the system generates inertial force through rotational acceleration (τ = Iα) rather than linear acceleration (F = ma). This parameter change allows achieving the same damping effect with significantly reduced mass and space occupation.
Solution Approach 2:
The patent employs active control through a driving device that dynamically adjusts the rotational speed and acceleration of the mass block based on real-time vibration detection. This dynamic adjustment allows the system to optimize damping performance adaptively, achieving effective vibration reduction with a smaller mass block compared to passive large-scale TMDs.
2Reliability
If a large-scale TMD is used to reduce vibration in large buildings, then the vibration reduction capability is improved, but the gravity force applied to the floor increases excessively
Solution Approach 1:
The patent fundamentally changes from linear mass motion to rotational mass motion. The inertial force in rotation is generated by angular acceleration acting on the moment of inertia (τ = Iα), which allows achieving sufficient damping force with much smaller mass. The rotational mass block of 1-10 tons replaces traditional linear TMDs of hundreds of tons, dramatically reducing gravity force on the floor.
Solution Approach 2:
The patent segments the traditional monolithic large-mass TMD into a compact rotational system with separated functional components: a relatively small rotational mass block, a lead screw mechanism, and an active driving device. This segmentation allows achieving the same damping function with distributed, lighter components rather than one large heavy mass.
3Device complexity
If a conventional TMD is used, then the system structure is simple, but the friction and inertial force prevent effective response to lower-level earthquakes or winds
Solution Approach 1:
The patent transitions from a passive TMD system to an active controlled system. The driving device receives feedback from vibration sensors and dynamically adjusts the rotational acceleration of the mass block to counteract vibrations in real-time. This active control overcomes the friction and inertial limitations of passive systems, enabling effective response to low-level earthquakes and winds that would otherwise be insufficient to activate a conventional TMD.
Solution Approach 2:
The patent implements a feedback control loop where vibration sensors detect building motion, the controller processes this information, and the driving device adjusts the rotational mass block accordingly. This closed-loop feedback system ensures the damper responds appropriately to varying vibration levels, overcoming the threshold activation problem of passive TMDs and maintaining effectiveness across different earthquake and wind intensities.
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 active inerter damper effectively reduces dynamic responses in building structures with a smaller footprint, enhancing vibration suppression without the need for extensive structural support, and providing adaptable damping for various building structures by determining the required rotational speed and force.
Implementation Method 1
The lead screw is movably disposed above the base along an axial direction. The rotational mass block is engaged with the lead screw so as to be rotatable with respect to the base.
Implementation Method 2
the inertial force generated by a rotating object is larger than that of the same object in linear oscillation movement. In this regard, a smaller mass of the rotational mass block will be able to generate a sufficient inertial force of rotation acting on the building structure.
Data Source
AI summary
This disclosure relates to an active inerter damper configured to be disposed on or in a building structure. The active inerter damper includes a base, a lead screw, a rotational mass block, a driving device and a controller. The lead screw is movably disposed above the base along an axial direction. The rotational mass block is engaged with the lead screw so as to be rotatable with respect to the base. The driving device is connected to the lead screw. The controller is electrically connected to the driving device, and the controller is configured to activate the driving device to move the lead screw along the axial direction so as to rotate the rotational mass block via the lead screw.