Double Variable Sliding Isolator Near-Field Earthquake Resonance
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Solution Overview
Problem
Existing seismic isolators, such as friction pendulum isolators, are prone to resonance during near-field earthquakes, leading to increased risk of failure and require larger sizes to enhance seismic isolation, which increases installation space and manufacturing costs.
Innovation Solution
A double variable sliding isolator with variable curvatures, comprising a bottom sliding plate, a top sliding plate, and a friction piece with curved surfaces, allowing for relative displacement and a non-linear relationship between restoring force and displacement, providing flexibility and smaller size compared to single-pendulum isolators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the size of the friction pendulum isolator is increased to improve seismic isolation efficiency and safety under near-field earthquakes, then the seismic isolation performance is improved, but the installation space occupation and manufacturing cost increase
Solution Approach 1:
The isolator is divided into two separate pendulum plates (upper and lower) with independent curved sliding surfaces, each contributing to the seismic isolation function. This segmentation allows each plate to be optimized independently for smaller size while maintaining overall isolation effectiveness through their combined action.
Solution Approach 2:
The invention transitions from a single-pendulum design to a double-pendulum configuration, adding another dimensional aspect to the isolation mechanism. The two pendulum plates work in series, creating a more efficient isolation path that reduces the required size of individual components.
2Device complexity
If the friction pendulum isolator is designed with constant curvature, then the structure is simple, but it causes resonance behavior in near-field earthquakes with long period components leading to excessive displacement
Solution Approach 1:
The curved sliding surfaces of the upper and lower pendulum plates are designed with different curvature radii (R1 for upper plate, R2 for lower plate). This local differentiation in curvature allows each surface to be optimized for specific seismic conditions, preventing resonance while maintaining structural simplicity.
Solution Approach 2:
The invention changes the curvature parameter from constant (single-pendulum) to variable (double-pendulum with different radii). By adjusting the curvature radii of the two pendulum plates, the system can adapt to different seismic excitation characteristics, particularly effectively handling near-field earthquakes with long period components.
3Volume of moving object
If a single-pendulum isolator is used, then the structure is compact, but under the same displacement capacity it requires larger size compared to the double variable sliding isolator
Solution Approach 1:
By segmenting the isolator into two pendulum plates with independent curved surfaces, the invention achieves better size efficiency. Each plate can be compact while their combined action provides the required displacement capacity, resulting in a smaller overall isolator size compared to single-pendulum designs.
Solution Approach 2:
The double-pendulum configuration introduces dynamic flexibility through the interaction between two independently curved sliding surfaces. This dynamic arrangement allows the isolator to adapt to various seismic conditions while maintaining a compact size, enhancing both versatility and size efficiency.
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 double variable sliding isolator effectively mitigates excessive displacement during near-field earthquakes, offering enhanced flexibility and suitability for various seismic isolation requirements while reducing size and cost compared to traditional isolators.
Implementation Method 1
The friction piece is slidably disposed between the top sliding plate and the bottom sliding plate and is in contact with the bottom sliding surface and the top sliding surface respectively. When an external force is applied to the bottom sliding plate and the top sliding plate, the bottom sliding plate and the top sliding plate will generate a relative displacement, so that the friction piece slides relative to the bottom sliding surface and the top sliding surface.
Data Source
AI summary
A double variable sliding isolator including a bottom sliding plate, a top sliding plate, and a friction piece is provided. The bottom sliding plate has a bottom sliding surface that has at least two curvatures. The top sliding plate is disposed over the bottom sliding plate and has a top sliding surface that has at least two curvatures. The friction piece is disposed between the top sliding plate and the bottom sliding plate and the friction piece is in contact with the bottom sliding surface and the top sliding surface. When an external force is applied to the bottom sliding plate and the top sliding plate, the bottom sliding plate and the top sliding plate will generate a relative displacement, so that the friction piece slides along the bottom sliding plate and the top sliding plate.