Rigid Substructure Damping System for Seismic Energy Dissipation
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Solution Overview
Problem
Existing damping systems for large structures, such as buildings, are expensive and inefficient in dissipating dynamic forces like earthquakes and winds, as they require complex mechanisms and significant structural modifications, limiting their applicability and cost-effectiveness, especially for low-rise buildings.
Innovation Solution
A rigid substructure damping system that incorporates a restrained column and anchor column with flexural members and damped diagonals, allowing for amplified displacement and energy absorption through rigid body rotation and bending, reducing the need for mechanical amplification and conventional bracing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If complex mechanical magnification systems are used to amplify damper displacement, then energy dissipation effectiveness is improved, but device complexity and construction cost increase significantly
Solution Approach 1:
The patent extracts the magnification function from complex mechanical systems and implements it through simple geometric configuration of the damper within the rigid substructure. The damper is positioned to directly utilize the relative displacement between the rigid substructure and main structure, eliminating the need for separate magnification mechanisms while maintaining effective energy dissipation.
Solution Approach 2:
The rigid substructure serves multiple functions simultaneously: it provides lateral stiffness to the building, creates amplified displacement for the damper through its geometric configuration, and enables effective energy dissipation without requiring additional specialized components. This multi-functionality resolves the contradiction by achieving magnification through the primary structural element rather than adding complex auxiliary systems.
2Force
If amplification mechanisms are added to increase damper displacement, then damper force requirements are reduced, but construction cost and structural modification requirements increase
Solution Approach 1:
The patent merges the magnification mechanism with the rigid substructure itself. The geometric configuration of the rigid substructure naturally produces amplified displacement at the damper location, combining the structural support function with the displacement amplification function in a single integrated system, thereby reducing construction cost while maintaining low damper force requirements.
Solution Approach 2:
The patent changes the geometric parameters of the rigid substructure (dimensions, configuration, placement) to optimize the displacement amplification ratio. By adjusting these parameters, the system achieves the desired damper displacement and force reduction without requiring expensive mechanical magnification devices or extensive structural modifications.
3Loss of energy
If rigid substructures with damped diagonals are used to amplify displacement, then energy absorption is improved, but structural material usage increases
Solution Approach 1:
The patent applies partial action by implementing the rigid substructure damping system in only the most critical regions of the building (typically upper stories where seismic forces are most significant). This selective application achieves effective energy absorption in the regions that need it most while minimizing overall material usage compared to full-building implementation.
Solution Approach 2:
The patent creates a composite system combining the rigid substructure (made of concrete or steel), the main building structure, and the viscous dampers. This composite approach allows the different materials to work together synergistically, with the rigid substructure providing stiffness, the dampers providing energy dissipation, and the main structure providing overall support, thereby achieving high energy absorption efficiency with optimized material distribution.
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
This system achieves significant energy absorption and performance improvement by amplifying axial deformations in dampers, reducing structural costs and maintaining stability with reduced material usage, enabling buildings to behave elastically under seismic loads.
Implementation Method 1
Dampers dissipate energy from a structural system by receiving displacement or velocity between two points of a structure
Implementation Method 2
the restrained segment of the column tilts and the rigid substructure undergoes rigid body rotation
Implementation Method 3
a flexural member, each connected to at least one active node and to an anchor node... the flexural member be bent, resisting the vertical displacement of the active node
Implementation Method 4
Increasing the displacement of a damper reduces the force exerted to the damper which reduces the cost for a viscous damper
Data Source
AI summary
A rigid substructure (12) tied to a restrained column (16) at different floors undergoes rigid body rotation due to lateral dynamic loading. Flexural members (18) that are connected to the substructure (12) and another anchor column (14) resist the rigid body rotation and undergo vertical deflections. Damped diagonals (20) connected to common nodes of the rigid substructure and flexural members, for one embodiment, receive amplified displacements and more effectively dissipate energy. Flexural members restore the structure to the unloaded position. The system does not require moment connections and can work with flexure induced in simply supported beams. The system is highly effective and may remain elastic under maximum considered earthquake ground motions.