Double-order multi-wave type buckling restrained brace
By setting a thinned surface and an unbonded layer on the core unit of the buckling-restrained brace, double-stage yielding and multi-wave buckling control are achieved, solving the problem of insufficient energy dissipation of the buckling-restrained brace in small or moderate earthquakes and improving the seismic performance of the building.
Patent Information
- Application Number
- CN202520131714.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2035-01-21
AI Technical Summary
Existing buckling-restrained braces are insufficient in energy dissipation capacity during minor or moderate earthquakes, and the location of multi-wave buckling is uncontrollable, leading to premature structural failure and affecting seismic performance.
A two-stage multi-wave buckling restraint brace is designed. By setting a thinned surface on the core unit and installing an unbonded layer, the development sequence and position of multi-wave buckling are controlled, and the two-stage yielding performance is achieved by utilizing the pre-yielding of the thinned surface.
It provides effective energy dissipation capacity in minor or moderate earthquakes, improves the seismic performance of the structure, avoids premature failure of core units, and enhances the overall lateral stiffness and hysteretic energy dissipation capacity.
Smart Images
Figure CN223766986U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of building vibration reduction technology, specifically a two-stage multi-wave buckling restraint brace. Background Technology
[0002] In the field of seismic engineering, traditional bracing structures often face the problem of compressive buckling under seismic loads. This buckling not only prevents the yield bearing capacity of the bracing structure from being fully utilized, but also significantly reduces the overall lateral stiffness and lateral bearing capacity of the structure, thus posing a serious threat to building safety. To solve this problem, researchers are constantly seeking new types of seismic bracing structures to improve the seismic performance of buildings.
[0003] Buckling-restrained braces (BRBs), a novel type of seismic bracing structure, have been widely used globally since their initial development in Japan in the 1970s. A BRB consists of three parts: a core element, restrained elements, and an unbonded layer. The restraint of the restrained elements prevents the core plate from buckling under compression, achieving full-section yielding and fully utilizing material properties. This bracing structure not only improves the lateral stiffness of the structure but also possesses excellent hysteretic energy dissipation capabilities, demonstrating significant energy dissipation and vibration reduction effects under seismic loading.
[0004] However, despite their excellent seismic performance, buckling-restrained braces (BRBs) have a high yield capacity and tend to remain elastic under smaller seismic loads, failing to provide effective energy dissipation for the structure. This means that the energy dissipation effect of BRBs is mainly manifested during large earthquakes, while their seismic resistance is not significant during minor or moderate earthquakes. Furthermore, BRBs exhibit multi-wave buckling upon compressive yielding, but the location of this multi-wave buckling is uncontrollable and may concentrate in a single area, leading to premature failure of the core unit under repeated tension and compression.
[0005] To overcome the aforementioned shortcomings of buckling-restrained braces, researchers have invented a novel type of buckling-restrained brace with bi-stage yielding characteristics and controllable multi-wave buckling. This novel buckling-restrained brace not only provides stable and effective energy dissipation capacity during large earthquakes but also functions effectively in minor or moderate earthquakes, improving the overall seismic performance of the structure. Utility Model Content
[0006] The purpose of this invention is to solve the problems in the prior art and provide a two-stage multi-wave buckling restraint brace.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: a two-stage multi-wave buckling restraint brace, comprising a core unit, a restraint unit, and an unbonded layer, wherein the core unit has thinned surfaces arranged at equal intervals on both sides, and an unbonded layer is fixedly installed on the thinned surfaces.
[0008] Furthermore, the top surface of the unbonded layer is higher than the initial surface of the core unit.
[0009] Preferably, the thinned surfaces are arranged symmetrically around the midpoint of the core unit.
[0010] Preferably, the thinned surface on the core unit transitions to the initial surface via a slope.
[0011] Preferably, the non-adhesive layer can be made of the same material or of different materials with different hardness.
[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0013] 1. By utilizing the mechanism of the thinned section in the core unit yielding first, a double-yield performance is achieved, which can better adapt to different seismic conditions.
[0014] 2. The thinned surface is more prone to buckling than the initial surface. At the same time, the installation of an unbonded layer on the thinned surface can perfectly match the compressibility of the unbonded layer.
[0015] 3. By installing unbonded layers of different hardness in the thinned surface, the development sequence of multi-wave buckling of the core unit can be artificially controlled. Attached Figure Description
[0016] Figure 1 This is a front view of the structure of this utility model.
[0017] Figure 2 This is a top view of the structure of this utility model.
[0018] Figure 3 This is a top view of the core unit of this utility model.
[0019] Figure 4 This is a schematic diagram of multi-wave buckling of a conventional buckling-restrained support.
[0020] Figure 5 This is a schematic diagram of the multi-wave buckling of this utility model.
[0021] In the figure: 1. Core unit; 1-1. Thinned surface; 2. Constraint unit; 3. Unbonded layer. Detailed Implementation
[0022] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.
[0023] Example: Figure 1-3As shown, a two-stage multi-wave buckling restraint brace includes a core unit, restraint units, and an unbonded layer. The core unit has thinned surfaces arranged at equal intervals on both sides, and the unbonded layer is fixedly mounted on these thinned surfaces. The top surface of the unbonded layer extends above the initial surface of the core unit. The thinned surfaces are symmetrically arranged around the midpoint of the core unit. The thinned surfaces on the core unit transition to the initial surface with a slope to prevent stress concentration. The unbonded layer can be made of the same material or of materials with different hardness.
[0024] The working principle of this invention is as follows: When the core element of the buckling-restrained brace buckles under compression, the core element gradually develops from single-wave buckling to multi-wave buckling, meaning that the core element generates multiple peaks and troughs within the length of the restrained element. For example... Figure 4 As shown, the distribution of multi-wave buckling in conventional buckling-restrained braces is not necessarily uniform and equidistant; it may be concentrated in a certain area. This can lead to premature fatigue failure of the core element at that location, thereby reducing the fatigue performance of the buckling-restrained brace. Figure 5 As shown, this invention creates a thinned surface on the core unit, making it more prone to buckling deformation compared to the initial surface. Simultaneously, an unbonded layer is installed on the thinned surface, providing deformation space for the buckling deformation occurring at the thinned surface, thus limiting the core unit to buckling deformation only at the thinned surface. Furthermore, the density of the unbonded layer can be controlled according to the deformation amount of the buckling restraint support.
[0025] Additionally, unbonded layers with varying hardness can be installed on different thinned surfaces, allowing for artificial control of the development sequence of multi-wave deformation on the core unit. For example, the hardness of the unbonded layer can gradually increase from the middle to both ends of the core unit. The core unit first buckles in the area with lower hardness of the unbonded layer, and then buckles in the area with higher hardness of the unbonded layer. In other words, the multi-wave buckling on the core unit gradually develops from the middle region to both ends.
[0026] When a buckling-restrained brace undergoes tensile or compressive deformation, the thinned segment corresponding to the thinned surface in the core unit, due to its smaller cross-sectional area compared to the initial segment corresponding to the initial surface, will first enter the yielding state, forming a first-order yield. It will then enter the strengthening state, and the axial force of the brace will continue to increase. When the axial force of the brace exceeds the yield force of the initial segment, the initial segment will then enter the yielding state, forming a second-order yield.
[0027] The above content is a further detailed description of the technical solution provided in conjunction with the preferred embodiments of this patent. It should not be considered that the specific implementation of this utility model is limited to the above description. For those skilled in the art to which this patent pertains, several simple deductions or substitutions can be made without departing from the concept of this patent, and all of these should be considered to fall within the protection scope of this patent.
Claims
1. A dual-stage multiple wave buckling-restrained brace, characterized by: The core unit, the constraint unit and the non-bonding layer are provided, the core unit is provided with the thinned surface arranged in equal interval and cross on both sides, the non-bonding layer is fixedly installed on the thinned surface, and the top surface of the non-bonding layer is higher than the initial surface of the core unit.
2. The dual-stage multi-wave buckling-restrained brace according to claim 1, characterized in that: The thinned surface is arranged symmetrically along the midpoint of the core unit.
3. The dual-stage multi-wave buckling-restrained brace according to claim 1, wherein: The thinned surface on the core unit is transitioned to the initial surface by the inclined surface.
4. The dual-stage multiple wave buckling-restrained brace according to claim 1, wherein: The non-bonding layer can be selected from the same material or different materials with different hardness.