CN105507132A - Torsional three-tube buckling restrained brace - Google Patents

Abstract

The invention relates to a torsion-type three-tube buckling restraint support, which includes a support body and end plates arranged at both ends of the support body. The support body includes internal restraint steel pipes, middle torsion steel pipes and external restraint steel pipes arranged sequentially from inside to outside. The internal restraint steel pipe and the external restraint steel pipe are round steel pipes, the lower end is fixedly connected to the end plate, and the upper end is suspended in the air, and the middle torsion steel pipe is a round steel pipe with a spiral groove in the middle, and the upper and lower ends are fixed to the end plate connect. Compared with the prior art, the invention has the advantages of high deformation performance, high fatigue life, good restraint, light weight and the like.

Description

A torsional three-tube buckling-restrained brace

technical field

The invention relates to the field of anti-seismic design of building bridge structures, in particular to a torsional three-pipe buckling-constrained support.

Background technique

Most of the existing buckling-constrained supports consume energy through the axial tensile deformation of the core material section, and the damage often occurs at the weld of the end stiffener or the end of the anti-slip block in the middle, resulting in a small maximum deformation of the support (the average strain is less than 3%), or a low yield point steel with high price but better ductility is needed to improve the ductility of the support. On the other hand, since the tangential stiffness of the steel after yielding tends to zero, the residual deformation of the buckling-constrained bracing structure system is relatively large, which has become its main disadvantage. With the frequent occurrence of large earthquakes in the world in recent years, the seismic resistance of structures has higher and higher requirements for the maximum deformation of supports and its ultra-low cycle fatigue performance, and at the same time, the requirements for the control of residual deformation after earthquakes are also higher and higher. How to ensure that the support can still work normally after being attacked by many major earthquakes, so as to ensure that it does not need to be replaced during its entire working life, the related design concepts are also getting more and more attention. At the same time, in order to improve the repairability of the structure, the post-yield strengthening stiffness of buckling-restrained braces is also required.

Contents of the invention

The object of the present invention is to provide a torsional three-tube buckling-constrained support with high deformation performance, high fatigue life, good restraint and light weight in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A torsion-type three-tube buckling-constrained support, including a support body and end plates arranged at both ends of the support body, the support body includes internally constrained steel pipes, middle torsion steel pipes and externally constrained steel pipes arranged in sequence from inside to outside, the described The internal restraint steel pipe and the external restraint steel pipe are round steel pipes, the lower end is fixedly connected to the end plate, and the upper end is suspended in the air. The middle torsion steel pipe is a round steel pipe with a spiral groove in the middle, and the upper and lower ends are fixedly connected to the end plate.

The torsion-type three-pipe buckling-constrained support further includes a plurality of end stiffeners, and the end stiffeners are respectively fixedly connected to the end plates and the upper and lower parts of the external constrained steel pipes.

The lengths of the internal restraint steel pipe and the external restraint steel pipe are both greater than the length of the twisted steel pipe in the middle where the helical groove is opened.

The twisted steel pipe in the middle is formed by cutting a round steel pipe or by cold working a flat plate.

The internal restraint steel pipe is a hollow structure.

A non-adhesive material is provided between the twisted steel pipe in the middle and the steel restraint outside, and a non-adhesive material is provided between the twisted steel pipe in the middle and the steel restraint inside.

Compared with the prior art, the present invention has the following advantages:

1. High deformation performance and high fatigue life: the invention is composed of three steel pipes, the inner part is a common steel pipe, the middle part is a partially weakened twisted steel pipe, the outer part is an ordinary round steel pipe, and the inner and outer steel pipes provide lateral restraint for the middle twisted steel pipe , because the torsional steel pipe in the middle is weakened, according to the principle of the torsional metal damper, the necking deformation will finally occur in the weakened section under large deformation.

2. Good restraint: through the welding of the inner and outer restraint steel pipes and the lower end plate, the relative rigid body motion between the inner restraint steel pipe and the middle twisted steel pipe is small, so as to improve the deformation capacity of the component under hysteretic loading such as earthquakes. The energy dissipation capacity is better than that of the double-pipe energy dissipation support.

3. Light weight: the present invention adopts the outer steel pipe after the middle part is weakened and the hollow inner steel pipe, which greatly reduces the quality of the present invention.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

FIG. 2 is a schematic structural view with a cross section in FIG. 1 .

Fig. 3 is a sectional view of section A-A in Fig. 1 .

Fig. 4 is a cross-sectional view of section B-B in Fig. 1 .

Fig. 5 is a sectional view of section C-C in Fig. 1 .

1. Internal restraint steel pipe, 2. Middle torsion steel pipe, 3. External restraint steel pipe, 4. Unbonded material, 5. End stiffener, 6. End plate.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example:

As shown in Figure 1-5, the middle part of the core twisted steel pipe is formed by cutting or cold-working the round steel pipe, and the round steel pipe section at the upper and lower ends is not weakened for connection with the upper and lower ends. The inner and outer steel pipes are welded to the lower end plate, and the length of the inner and outer steel pipes is longer than that of the torsion steel pipe in the middle, so as to provide constraints for the buckling resistance of the torsion steel pipe in the middle and prevent buckling failure under large deformation. At the same time, the inner steel pipe, the outer steel pipe and the middle steel pipe are filled with non-bonded material to reduce the friction force between the three due to contact. The assembly process is as follows: first make the middle twisted steel pipe, then attach the inner and outer steel pipes with non-adhesive materials, and weld them with the lower end plate in turn; weld the middle steel pipe with the stiffener and the upper end plate.

The technical problem to be solved in the present invention is: to overcome the deficiencies of the background technology, to propose a light-weight all-steel torsion-type double-tube buckling-constrained support with high deformation performance and high fatigue life, which is composed of three steel pipes, and the inside is an ordinary steel pipe , the central part is a partially weakened twisted steel tube, the outer part is an ordinary round steel tube, and the inner and outer steel tubes provide lateral restraint for the central twisted steel tube. The specific technical scheme of torsional buckling-restrained bracing is: the components include internally constrained steel pipes, unbonded materials, middle torsion-type steel pipes, externally constrained steel pipes, end plates and stiffeners, and the main components are made of steel, which greatly reduces the braced self-respect. Among them, the torsional steel pipe in the middle is weakened, and the necking deformation under large deformation will eventually occur in the weakened section, instead of the general buckling restraint support. Through the welding of the inner and outer restraint steel pipes and the lower end plate, the relative rigid body motion between the inner restraint steel pipe and the middle twisted steel pipe is small, so as to achieve the effect of improving the deformation capacity of the component under hysteretic loading such as earthquakes. Compared with the double-pipe energy-dissipating support better energy consumption. In addition, the axial deformation of the support will be converted into the torsional deformation of the steel tube in the middle, thus acting as a torsional metal damper. As we all know, the torsional deformation capacity of the round steel pipe is very good, and the corresponding hysteretic characteristics are stable, and it has a large tangential stiffness after yielding, so that the support not only has a stable and excellent cyclic energy dissipation capacity, but also has a large The second-order stiffness can greatly improve the seismic performance and post-earthquake repairability of the structure.

Claims (6)

1. a twist mode three pipe buckling restrained brace, comprise supportive body and the end plate (6) being arranged on supportive body two ends, it is characterized in that, described supportive body comprises the internal constraint steel pipe (1) set gradually from inside to outside, steel pipe (2) and external constraint steel pipe (3) are reversed in middle part, described internal constraint steel pipe (1) and external constraint steel pipe (3) are round steel pipe, lower end is fixedly connected with end plate (6), upper end is unsettled, described middle part is reversed steel pipe (2) for middle part and is offered the round steel pipe of spirality grooving, upper and lower two ends are all fixedly connected with end plate (6).

2. a kind of twist mode three pipe buckling restrained brace according to claim 1, it is characterized in that, described twist mode three pipe buckling restrained brace also comprises multiple end stiffener rib (5), and described end stiffener rib (5) is fixedly connected with the upper and lower of end plate (6) and external constraint steel pipe (3) respectively.

3. a kind of twist mode three pipe buckling restrained brace according to claim 1, it is characterized in that, described internal constraint steel pipe (1) and the length of external constraint steel pipe (3) are all greater than middle part and reverse the length that steel pipe (2) offers spirality slot portion.

4. a kind of twist mode three pipe buckling restrained brace according to claim 1, is characterized in that, steel pipe (2) is reversed by round steel pipe cutting forming or by dull and stereotyped cold-formed in described middle part.

5. a kind of twist mode three pipe buckling restrained brace according to claim 1, is characterized in that, described internal constraint steel pipe (1) is hollow structure.

6. a kind of twist mode three pipe buckling restrained brace according to claim 1, it is characterized in that, described middle part is reversed and is provided with without adhesives (4) between steel pipe (2) and external constraint steel pipe (3), and described middle part is reversed between steel pipe (2) and internal constraint steel pipe (1) and is provided with without adhesives (4).