WO2023125066A1

WO2023125066A1 - Core energy consuming structure capable of being partially fused for dual-order energy consumption, and axial steel damper

Info

Publication number: WO2023125066A1
Application number: PCT/CN2022/139512
Authority: WO
Inventors: 杨旗; 王敏; 丁孙玮; 杨凯; 涂田刚; 洪彦昆; 徐斌
Original assignee: 上海材料研究所有限公司
Priority date: 2021-12-27
Filing date: 2022-12-16
Publication date: 2023-07-06
Also published as: CN114277951B; CN114277951A

Abstract

The present invention relates to a core energy consuming structure capable of being partially fused for dual-order energy consumption, and an axial steel damper. The axial steel damper comprises the core energy consuming structure and a peripheral constraint member, the core energy consuming structure at least comprises an austenitic structure steel plate and a ferrite structure steel plate, and the austenitic structure steel plate and the ferrite structure steel plate are connected without constraint. A microstructure of the austenitic structure steel plate is mainly metastable austenite, and a microstructure of the ferrite structure steel plate is mainly ferrite; and the austenitic structure steel plate has yield strength not less than 220 MPa and an elongation not less than 40%, and the ferrite structure steel plate has yield strength less than 180 MPa and an elongation not less than 30%. The axial steel damper in the present invention has characteristics of small yield displacement, excellent ductility and cumulative plastic deformation performance, being able to achieve partial fusion of the core energy consuming structure so as to limit output of the damper, and being able to fail with the same redundancy as a building main structure.

Description

Partially fusible double-stage energy dissipation core energy dissipation structure and axial steel damper

technical field

The invention belongs to the technical field of building engineering structures, and relates to a core energy-dissipating structure and an axial steel damper which can partially fuse two-stage energy-dissipating.

Background technique

Both high-intensity earthquakes and long-lasting external vibrations will cause great harm to high-rise buildings and structures. The use of energy-dissipating and shock-absorbing devices and technologies can effectively absorb external shock energy and minimize damage to buildings and structures. Buckling-resistant energy-dissipating brace is a common axial energy-dissipating shock-absorbing element, which is widely used in civil engineering structures because of its direct force transmission path, high additional stiffness, and good economy.

At present, anti-buckling energy-dissipating braces mainly use steel such as LY225 low-yield point steel and Q235 structural steel as energy-dissipating core materials (the above-mentioned steel types are all low-carbon ferritic steels). The anti-buckling energy-dissipating bracing made of the above-mentioned steel types can only provide a certain degree of stiffness and cannot start a substantial Yield deformation to dissipate seismic energy. More critically, due to the low ductility and low cycle fatigue deformation capacity of steel types, the cumulative plastic deformation and cumulative plastic energy dissipation effect of the above steel types caused by cyclic deformation are limited. Therefore, under rare earthquakes ('big earthquakes'), buckling-resistant energy-dissipating braces made of the above-mentioned steel types will undergo fatigue fracture after fewer cycles of tension-compression cyclic loading; and, in rare earthquakes Or under extremely rare earthquakes, the anti-buckling energy-dissipating brace cannot achieve the same redundancy failure as the main structure of the building (that is, the anti-buckling energy-dissipating brace fails earlier than the failure of the main structure of the building, so that the main structure of the building cannot obtain buckling-proof Further protective effect of energy-dissipating support). In addition, the limit output force of existing anti-buckling energy-dissipating supports is often relatively large. A larger limit output will cause a greater burden on the connecting nodes, which may cause the connecting nodes to be damaged before the energy-dissipating components, so that the basic anti-seismic idea of "strong nodes and weak components" cannot be realized. Here, the connection node refers to the component that fixedly connects the anti-buckling energy-dissipating support (or the axial energy-dissipating shock-absorbing element) to the beam-column structure of the building. To sum up, the existing anti-buckling energy-dissipating braces made of low-carbon ferritic steel core materials cannot play the role of shock absorption and protection under earthquakes of different intensities. In addition, the existing anti-buckling energy-dissipating supports need to be designed and manufactured according to the oblique dimensions of the main structural frame, and the size of the energy-dissipating supports is generally large, which is not conducive to on-site installation and post-earthquake replacement.

Contents of the invention

Based on the above technical status, there is an urgent need to develop an axial steel damper with small yield displacement, excellent ductility and cumulative plastic deformation capacity, which can limit the output of the damper, and can fail at the same redundancy as the main structure of the building. Therefore, the present invention provides a partially fusible double-stage energy dissipation core energy dissipation structure and an axial steel damper.

The axial steel damper provided by the present invention can play the role of energy dissipation and shock absorption under different intensities of earthquakes and protect buildings against earthquakes; and when the output of the axial steel damper reaches a certain level, the energy dissipation structure of the core Partial fusing, the ultimate output of the damper is limited to ensure the reliability of the connecting node under rare or ultra-rare earthquakes.

Compared with the existing anti-buckling energy-dissipating support, the core energy-dissipating structure and the axial steel damper of the present invention have a small yield displacement, excellent ductility and cumulative plastic deformation capacity, and can be integrated with the main structure of the building. Characteristics of the same redundancy failure. The partially fusible double-stage energy-dissipating axial steel damper of the present invention can play the role of energy dissipation and shock absorption under different intensities of earthquakes and can protect buildings against earthquakes; and, when the output of the axial damper reaches a certain level, the damper The energy-dissipating structure of the core is partially fused, and the limit output of the damper is limited. In addition, the double-stage energy-dissipating axial steel damper of the present invention can be connected and combined with other steel supports to form an axial energy-dissipating support, which meets the requirements of prefabricated buildings and rapid replacement after earthquakes.

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

The present invention firstly provides a core energy dissipation structure with partially fusible double-stage energy dissipation, which is used for the axial steel damper, and absorbs external vibration when the axial steel damper is subjected to periodic alternating tension-compression plastic deformation the effect of energy,

The partially fusible double-stage energy dissipation core energy dissipation structure includes at least one austenitic structure steel plate and one ferrite structure steel plate, and there is no gap between the ferrite structure steel plate and the austenite structure steel plate Constrained connections,

The microstructure of the austenitic steel plate is composed of metastable austenite and thermally induced ε martensite with a volume fraction of no more than 15%, and the average grain size of the metastable austenite is no more than 400 μm; During tensile or compressive plastic deformation, the metastable austenite of the austenitic steel plate induces the ε martensitic transformation under the action of strain and the α′ martensitic transformation is suppressed; During stretch-compression plastic deformation, a reversible phase transformation between austenite and strain-induced ε martensite occurs inside the austenitic steel plate. The microstructure of the ferritic steel plate is mainly ferrite, and the average grain size of ferrite is not more than 200 μm;

The yield strength of the austenitic steel plate is not less than 220MPa, and the elongation at break is not less than 40%, and the yield strength of the steel plate with ferrite structure is less than 180MPa, and the elongation at break is not less than 30%;

In the energy-dissipating structure of the core, the ratio of the sum of the cross-sectional areas of the core energy-dissipating sections of all ferritic steel plates to the sum of the cross-sectional areas of the core energy-dissipating sections of all austenitic steel plates is not less than 0.4.

The present invention stipulates that: in the core energy dissipation structure, if the cross-sectional geometry of the steel plate with ferrite structure or steel plate with austenite structure remains unchanged along the length direction, then the steel plate with ferrite structure or steel plate with austenite structure The core energy-consuming section of the steel plate is the full length of the steel plate with ferrite structure or austenite structure. At this time, the cross-section of the core energy-consuming section of the steel plate with ferrite structure or austenite structure is is the cross-section of the ferritic steel plate or austenitic steel plate; if the cross-sectional geometric shape of the ferritic steel plate or austenitic steel plate presents the characteristics of wide ends and narrow middle along the length direction, then The core energy-consuming section of the steel plate with ferrite structure or steel plate with austenite structure is the narrow part in the middle of the steel plate with ferrite structure or steel plate with austenite structure. At this time, the steel plate with ferrite structure or austenite structure The cross-section of the core energy-dissipating section of the steel plate with the ferrite structure is the cross-section of the narrow part in the middle of the steel plate with the ferrite structure or the steel plate with the austenite structure.

According to the present invention, the partially fusible double-stage energy dissipation core energy dissipation structure includes at least one steel plate with austenite structure and one steel plate with ferrite structure. The microstructure of the austenitic steel plate is metastable austenite and thermally induced ε martensite with a volume fraction of no more than 15%, the purpose of which is to promote the strain of the steel plate under the action of tension-compression alternating load Induce the formation of sheet-like ε martensite with single-morph crystallographic characteristics, avoiding the strong interaction between heat-induced ε martensite and strain-induced ε martensite in the original matrix structure, thereby promoting austenite and strain Induce the reversible phase transformation between ε martensite, reduce the generation of crystal defects in the matrix of austenitic steel plate and delay the expansion of fatigue cracks, so that the austenitic steel plate shows excellent low cycle fatigue performance and cumulative plastic deformation capacity. In addition, the present invention defines that the metastable austenite inside the austenitic steel plate is restrained from the α' martensitic transformation during tensile or compressive deformation. This is because, when the metastable austenite undergoes excessive α′ martensitic transformation under the action of plastic strain, deformation localization will easily occur inside the steel plate, resulting in a sharp decline in the low cycle fatigue performance of the austenitic steel plate . The present invention limits the average grain size of the metastable austenite to not exceed 400 μm. This is because when the austenite grains are too coarse, the reversible transformation between austenite and strain-induced ε martensite will be significantly inhibited, thereby significantly reducing the fatigue resistance of the austenitic steel plate. The present invention strictly limits the microstructure of the austenitic structure steel plate, and its purpose is to ensure that the austenitic structure steel plate can withstand large strain fatigue deformation, and ensure that the axial steel damper can withstand medium and high-intensity earthquakes and ultra-rare earthquakes. It can play a role without premature failure of fatigue failure, ensuring that the axial steel damper has the same redundancy failure function as the main structure of the building.

The ferrite structure steel plate has low yield strength, high elastic modulus and low work hardening degree within cyclic deformation cycles. Therefore, before the core energy-dissipating structure of the axial steel damper is partially fused, the ferrite steel plate helps to reduce the overall energy-dissipating structure of the core (when the core energy-dissipating structure is used for the axial steel damper , that is, the yield force and yield displacement of the axial steel damper) and the degree of work hardening within the cycle of cyclic deformation, so that the steel damper can achieve yield deformation energy dissipation under small and moderate earthquakes. However, the low cycle fatigue performance of the ferritic steel plate is lower than that of the austenitic steel plate. This is because: during the cyclic deformation of the ferritic steel plate, due to the frequent occurrence of cross-slip and the irreversible plastic deformation on the microscopic level, the material shows a continuous decrease in structural stability and a continuous increase in the localization of plastic strain; the cumulative strain increases with the cycle , the fatigue crack will nucleate from the strain incompatibility of the material surface (such as grain boundary, ferrite/cementite phase boundary) or the resident slip zone, and then grow along the grain boundary or into the grain until the material Intergranular or transgranular fatigue failure occurs. The present invention limits the average grain size of ferrite to not more than 200 µm. This is because when the ferrite grains are too coarse, fatigue cracks will easily initiate and propagate from the grain boundaries, thereby significantly reducing the fatigue resistance of the ferrite structure steel plate. Therefore, the restriction on ferrite grain size (and elongation) is aimed at ensuring proper fatigue resistance of ferritic steel plates.

In the partially fusible double-stage energy-dissipating core energy-dissipating structure of the present invention, the ferrite structure steel plate and the austenite structure steel plate are unconstrainedly connected. This is because, when the austenitic structure steel plate and the ferrite structure steel plate are connected by any means (such as welding), since the austenitic structure steel plate has a relatively higher yield strength than the ferrite structure steel plate (and deformation resistance) and the degree of work hardening, the austenitic steel plate will form constraints on the deformation of the ferritic steel plate, and this constraint will lead to fatigue failure of the core energy-dissipating components almost instantaneously in the same section, that is, austenitic The tennitic structure steel plate and the ferrite structure steel plate fracture in the same section at the same time, so the demand for limiting the output of the axial steel damper is not easy to achieve. When the steel plate with ferritic structure and the steel plate with austenitic structure are unconstrainedly connected, the constraint mechanism of the steel plate with austenitic structure on the deformation of the steel plate with ferritic structure does not exist. Since the yield strength and fatigue resistance of ferritic steel plates are significantly lower than those of austenitic steel plates, in the process of alternating tensile-compression plastic deformation, ferritic steel plates will first undergo yield deformation and fatigue fracture. As a result, the energy-dissipating structure of the core is partially fused, and the output of the axial steel damper is limited; subsequently, the austenitic steel plate in the energy-dissipating structure of the core continues to undergo periodic tensile-compressive deformation and dissipate external vibration energy. Until the steel damper finally fails completely. Usually, the steel plate with austenitic structure and the steel plate with ferritic structure are fractured in different sections. Therefore, the material selection and core energy-dissipating structure design of the present invention ensure that the axial steel damper has the effect of grading energy consumption and limiting output, and at the same time enables the axial steel damper to play the role of energy dissipation and shock absorption under earthquakes of different intensities effect.

The invention limits that the yield strength of the austenitic steel plate constituting the core energy dissipation structure is not less than 220MPa, and the elongation at break is not less than 40%; the yield strength of the steel plate with ferrite structure is less than 180MPa, and the elongation at break is not less than 30%. The main purpose of limiting the mechanical properties of the two types of steel plates is to ensure that the two types of steel plate materials have excellent plastic deformation capacity and fatigue properties as much as possible (although the plastic deformation capacity and fatigue properties of austenitic steel plates are significantly better than those of ferrite steel plates). body tissue steel plate), so that the axial steel damper has a good cumulative plastic deformation capacity before and after partial fusing of the core energy-dissipating structure, and meets the following technical performance indicators: the ratio of the limit allowable displacement to the yield displacement is equal to Less than 18, and the limit allowable displacement is not less than 1/50 of the length of the axial steel damper; and, under the limit allowable displacement condition, the axial steel damper can complete at least 3 cycles of periodic alternating tension-compression plastic deformation And the bearing capacity attenuation is less than 15%; and, when the core energy dissipation structure of the axial steel damper is partially fused, the axial steel damper can still be able to Complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%. Since the limit allowable displacement is not less than 1/50 of the length of the axial steel damper, the partially fusible double-stage energy dissipation core energy dissipation structure of the present invention can achieve the same redundancy as the main structure of the building when used in the axial steel damper invalidated.

Here, it needs to be explained that when the yield strength of the ferritic steel plate is smaller, and the difference between the yield strength of the ferritic steel plate and the austenitic steel plate is larger, the yield displacement of the axial steel damper is smaller. Under small earthquakes and moderate earthquakes, the energy consumption effect can be brought into play more. On the contrary, increasing the strength of the ferritic steel plate will not only increase the yield displacement, but also generally reduce the elongation and low cycle fatigue performance of the ferritic steel plate, which is not conducive to the sufficient cumulative plasticity of the core energy dissipation structure. Shapeshifting ability.

In the present invention, if the ratio of the sum of the cross-sectional areas of the core energy-consuming sections of all ferritic steel plates to the sum of the cross-sectional areas of the core energy-consuming sections of all austenitic steel plates is too small (less than 0.4), the core Before partial fusing of the energy-dissipating structure, its deformation and bearing are mainly dominated by the austenitic steel plate, which will significantly increase the yield displacement of the energy-dissipating structure at the core, which will not only cause small displacement conditions (that is, "small earthquakes") The energy dissipation efficiency of the lower core dissipative structure is not significant, and the ductility of the core dissipative structure and the axial steel damper is significantly reduced. Therefore, the present invention limits the ratio of the sum of the cross-sectional areas of the core energy-consuming sections of all ferritic steel plates to the sum of the cross-sectional areas of the core energy-consuming sections of all austenitic steel plates not less than 0.4; further, from reducing the core Considering the yield displacement of the internal energy-dissipating structure, it is preferable that the ratio of the sum of the cross-sectional areas of the core energy-dissipating sections of all ferritic steel plates to the sum of the cross-sectional areas of the core energy-dissipating sections of all austenitic steel plates is not less than 0.8.

The present invention defines the limit allowable displacement (u _{d, max} ) and yield displacement (u _dy ) of the axial steel damper as follows. Since the energy-dissipating structure of the core of the axial steel damper will be partially fused after the output of the axial steel damper reaches a certain level, the above limit allowable displacement (u _d,max ) is the energy dissipation of the axial steel damper in its core The maximum displacement allowed when the structure continues to undergo cyclic tension-compression plastic deformation after partial fusing, and under this maximum displacement condition, the steel damper can complete at least 3 cycles of tension-compression deformation without failure . When the cyclic deformation displacement exceeds the above-mentioned limit allowable displacement, the axial steel damper cannot complete 3 cycles of tension-compression cyclic deformation before fatigue failure. When the axial steel damper undergoes periodic alternating tension-compression plastic deformation with the maximum allowable displacement before the energy-dissipating structure of its core is partially fused, the displacement corresponding to the yield deformation of the damper is called the yield displacement (u _dy ). Here, it is still stipulated that the maximum permissible displacement of the energy-dissipating structure of the steel damper core before partial fusing occurs when the energy-dissipating structure of the steel damper core can withstand at least 3 cycles of tensile-compression plastic deformation before partial fusing occurs. The maximum displacement allowed. Figure 1 illustrates the hysteresis curves of the axial steel damper with the maximum permissible displacement for periodic alternating tension-compression deformation before partial melting of the energy-dissipating structure of the core and the same displacement after the partial melting of the energy-dissipating structure of the core Hysteretic curves for periodic alternating tension-compression deformation. The elastic stiffness of the axial steel damper is obtained from the unloading section of the hysteretic curve of the cyclic deformation with the maximum allowable displacement before partial fusing of the energy-dissipating structure of the core. The elastic stiffness corresponding to the unloading section of the tensile part of the hysteretic curve is

The elastic stiffness corresponding to the unloading section of the compression part of the hysteresis curve is

if

Then the elastic stiffness K _d of the axial steel damper is calculated as

if

At this time there is the elastic stiffness of the axial steel damper

A straight line whose slope is the elastic stiffness K _d is drawn through the coordinate origin, and the intersection point of the straight line with the stretched part of the hysteresis curve is the yield displacement during cyclic deformation stretching

The intersection of the straight line and the compression part of the hysteresis curve is the yield displacement during cyclic deformation compression

The yield displacement u _dy of the axial steel damper is calculated as

From the limit allowable displacement u _d,max and the yield displacement u _dy , the ratio of the limit allowable displacement u _d,max to the yield displacement u _dy of the axial steel damper can be obtained (used to characterize the ductility of the steel damper) .

In one embodiment of the present invention, further, the present invention limits the mass percentage of the chemical composition of the austenitic steel plate to be: C≤0.15%, 20.0%≤Mn≤34.0%, 3.5%≤Si≤6.0% , Al ≤ 2.5%, Ni ≤ 5.0%, Cu ≤ 2.0%, P ≤ 0.03%, S ≤ 0.03%, N ≤ 0.02%, and the rest are Fe and unavoidable impurity elements, among which, the mass of Al, Ni and Cu is 100%. Min content also satisfies the following relationship: Ni/Cu≥0.25 and Al+0.4Ni+0.25Cu≤3.5%.

Materials meeting the above compositional requirements have a microstructure of metastable austenite and thermally induced ε martensite with a volume fraction of not more than 15%, and the metastable austenite is subjected to tension-compression alternating loads Reversible ε martensite transformation occurs (that is, metastable austenite and strain-induced ε martensite undergo mutual transformation under alternating loads) and α′ martensite transformation is inhibited, so that the steel plate material Has excellent low cycle fatigue properties.

Under the premise of not changing the above basic microstructure characteristics, the chemical composition of the austenitic steel plate may also contain a small amount of Cr element; the mass percentage of Cr element is limited in the present invention: Cr≤2%. When it has the above alloy composition and the average grain size of the metastable austenite is not more than 400 μm, the yield strength of the austenitic steel plate is not less than 220 MPa, and the fracture elongation is not less than 40%.

In one embodiment of the present invention, further, the present invention also defines the mass percentages of the chemical components of the ferritic steel plate as follows: C≤0.1%, Mn≤1.0%, Si≤0.8%, Ti≤0.15%, Nb≤0.1%, V≤0.2%, P≤0.03%, S≤0.03%, N≤0.02%, and the rest are Fe and unavoidable impurity elements.

Materials meeting the above compositional requirements have a microstructure that is predominantly ferrite. Under the premise of not changing the above-mentioned basic microstructure characteristics, the chemical composition of the ferritic steel plate can also contain a small amount of Cu, Cr and Ni elements; the mass percentage of Cu, Cr and Ni elements limited by the present invention is: Cu≤0.5 %, Cr≤1%, Ni≤1%. When it has the above alloy composition and the average grain size of ferrite is not more than 200 μm, the yield strength of the steel plate with ferrite structure is less than 180 MPa, and the elongation at break is not less than 30%.

In one embodiment of the present invention, the cross-section of the core energy dissipation structure may have any type of axisymmetric geometry. The cross-sectional forms with any type of axisymmetric geometry mainly include cross-shaped, I-shaped and so on.

In one embodiment of the present invention, the core energy dissipation structure of the partially fusible double-stage energy dissipation axial steel damper can adopt a cross-sectional form with a narrow center and wide ends, as shown in Figure 2. When the two types of steel plates have geometric shapes that are wide at both ends and narrow in the middle (the narrow part in the middle of the steel plate is called the core energy-dissipating section), the narrow part in the middle of the core energy-dissipating structure composed of the two types of steel plates is called the core The core energy consumption section of the internal energy consumption structure. Since the axial steel damper is connected to the beam-column main structure of the building or other steel supports through connecting nodes or other connecting members, the above-mentioned cross-sectional geometric design of the core energy dissipation structure of the steel damper is to make the axial steel damper The plastic deformation of the damper is only concentrated in the core energy-dissipating section of the core energy-dissipating structure, avoiding obvious yield deformation or even failure of the connecting nodes or other connecting components during the service of the steel damper. The reasonable selection of the ratio of the cross-sectional area of the core energy-dissipating section to the two ends of the core energy-dissipating structure mainly depends on the material strength of the core energy-dissipating structure and connecting nodes or other connecting members, as well as the connection strength between the two. In principle, the yield force of the connecting nodes or other connecting components needs to be greater than the yield force of the core energy-dissipating structure when yielding.

In the present invention, as shown in Figure 2, increasing the ratio of the core energy-dissipating section length _L0 of the austenitic structure steel plate to the core energy-dissipating section length _l0 of the ferrite structure steel plate in the energy-dissipating structure of the core part is helpful It is used to increase the dissipation energy of the axial steel damper under small and moderate earthquakes.

The present invention also provides a partially fusible double-stage energy dissipation axial steel damper, comprising the partially fusible double-stage energy dissipation core energy dissipation structure and peripheral constraining components, the partially fusible double-stage energy dissipation core The energy-dissipating structure of the core plays the role of absorbing external shock energy when the axial steel damper is subjected to periodic alternating tension-compression plastic deformation, and the peripheral constraining members restrain the lateral displacement of the energy-dissipating structure of the core, Prevent buckling and instability of the core energy-dissipating structure.

In one embodiment of the present invention, the peripheral constraining member of the partially fusible double-stage energy-dissipating axial steel damper is selected as a constraining sleeve formed by a combination of steel pipes and filled concrete, or a reinforced concrete constraining sleeve, or Pure steel structural constraints.

In one embodiment of the present invention, the partially fusible double-stage energy-dissipating axial steel damper is installed in buildings and structures, and is connected with the beam-column main structure and connection nodes of buildings or structures to form an integral body, It plays the role of dissipating external vibration energy, which can significantly improve the seismic performance of buildings or structures.

In one embodiment of the present invention, the partially fusible double-stage energy-dissipating axial steel damper can be connected with other steel supports through a flange or an intermediate connecting plate to form an axial energy-dissipating support in combination to meet the assembly requirements. Type buildings and quick replacement requirements after earthquakes. Therefore, the structural size of the axial steel damper of the present invention can generally be smaller than that of conventional anti-buckling energy-dissipating supports, and its own weight is lighter. Figure 3 is a schematic diagram of an axial energy-dissipating support formed by a replaceable partially fusible two-stage energy-dissipating axial steel damper combined with other steel supports, and its three-dimensional model schematic diagram is shown in Figure 4. One end of the axial steel damper is connected to the building gusset plate through an intermediate connecting plate and a ball joint, and the other end of the axial steel damper is connected with other steel supports through an intermediate connecting plate or a flange to form an axial loss Can support.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1) Compared with the existing anti-buckling energy-dissipating support (the core energy-dissipating structure is usually made of LY225 or Q235 steel plate), the core energy-dissipating structure of the partially fusible double-stage energy-dissipating axial steel damper of the present invention has yield Small displacement, excellent ductility and cumulative plastic deformation capacity, and can fail at the same redundancy as the main structure of the building; and, when the output of the axial damper reaches a certain level, the core energy-dissipating structure of the damper is partially fused, and the limit output of the damper get restricted. The existing anti-buckling energy-dissipating brace does not have the above-mentioned technical features.

2) The axial steel damper of the present invention can be combined with other steel supports to form an axial energy-dissipating support, which meets the requirements of prefabricated buildings and rapid replacement after earthquakes. The structural size and self-weight of the axial steel damper of the present invention can be smaller than the structural size and self-weight of conventional anti-buckling energy-dissipating supports.

3) In the present invention, the steel plate with austenitic structure constituting the energy-dissipating structure of the core in the steel damper undergoes a reversible phase transformation between austenite and strain-induced ε martensite during the process of alternating tension-compression plastic deformation Therefore, the austenitic steel plate has excellent fatigue deformation performance, so that the steel damper has a very high limit allowable displacement and can achieve the same redundancy failure as the main structure of the building. If the austenitic steel plate used in the energy-dissipating structure of the core of the axial steel damper only undergoes a deformation mechanism of dislocation plane slip under cyclic loading, the corresponding mass percentage of the chemical composition of the austenitic steel plate can be expressed as 0.4%≤C≤0.7%, 16.0%≤Mn≤26.0%, Si≤2.0%, P≤0.02%, S≤0.03%, N≤0.03%, the rest is Fe and unavoidable impurity elements, then the axial Although the ductility and cumulative plastic deformation capacity of the steel damper can be better than that of the existing anti-buckling energy-dissipating brace, it will be significantly lower than the partially fusible two-stage energy-dissipating axial steel damper of the present invention.

Description of drawings

Fig. 1 illustrates the hysteresis curves of the partially fusible double-stage energy-dissipating axial steel damper before the core energy-dissipating structure is partially fused, and the hysteresis curves of the periodic alternating tension-compression deformation at the maximum allowable displacement and after the core energy-dissipating structure Hysteretic curves of periodic alternating tension-compression deformation with the same displacement after partial fusing.

Fig. 2 is a schematic diagram of a core energy-dissipating structure of a partially fusible two-stage energy-dissipating axial steel damper.

Fig. 3 is a schematic diagram of an axial energy-dissipating support formed by combining a partially fusible two-stage energy-dissipating axial steel damper with other steel supports.

Fig. 4 is a schematic diagram of a three-dimensional model of an axial energy-dissipating support formed by a combination of a partially fusible two-stage energy-dissipating axial steel damper and other steel supports.

Fig. 5 is the geometric shape of the austenitic steel plate constituting the energy dissipation structure of the core part of the fusible double-stage energy dissipation axial steel damper in embodiment 1.

Fig. 6 is the geometric shape of the ferrite structure steel plate constituting the energy dissipation structure of the core part of the fusible double-stage energy dissipation axial steel damper in embodiment 1.

Fig. 7 is a front view of the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 8 is a plan view of the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 9 is a side view of the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 10 is a front view of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 11 is a top view of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 12 is an A-A sectional view of the partially fusible two-stage energy-dissipating axial steel damper in Embodiment 1.

Fig. 13 is the hysteresis curve of the periodic alternating tension-compression plastic deformation of the partially fusible double-stage energy-dissipating axial steel damper in embodiment 1 before partial fusing occurs. The tensile (or compressive) displacements corresponding to the deformation hysteresis curves are 3mm, 9mm, 17mm, 25mm and 31mm respectively. Under each displacement condition, three cycles of deformation were experienced.

Fig. 14 is the hysteresis curve of the partially fusible double-stage energy-dissipating axial steel damper in embodiment 1 during the periodical alternating tension-compression plastic deformation when partial fusing occurs. The tensile (or compressive) displacements corresponding to the deformation hysteresis curves are 34mm and 37mm respectively. Under each displacement condition, three cycles of deformation were experienced.

Fig. 15 is the hysteresis curve of the partially fusible double-stage energy-dissipating axial steel damper in embodiment 1 when it undergoes periodic alternating tension-compression plastic deformation after partial fusing. The tensile (or compressive) displacements corresponding to the deformation hysteresis curves are 41mm, 50mm, 56mm, 63mm and 67mm respectively. Under each displacement condition, three cycles of deformation were experienced.

Labels in the figure: 1. Steel plate with ferrite structure; 2. Steel plate with austenite structure; 3. Concrete; 4. Peripheral restraint steel pipe; 5. Axial steel damper; 6. Intermediate connecting plate; 7. Steel support; , Ball hinge.

Detailed ways

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

Example 1:

A partially fusible two-stage energy-dissipating axial steel damper consists of a core energy-dissipating structure and peripheral restraint members.

The cross-section of the core energy-dissipating structure has a cross-shaped axisymmetric geometry, and its symmetry axis is the axial direction of the steel damper. The cross-section is narrow in the middle and wide at both ends along the axial direction. As shown in Figure 2, the core energy-dissipating structure is composed of one austenitic steel plate 2 and two ferritic steel plates 1, the austenitic steel plate 2 and the ferritic steel plate 1 have the same longitudinal length; 2 A ferritic steel plate 1 is placed above and below the austenitic steel plate 2 respectively, taking the longitudinal centerline of the austenitic steel plate 2 as the axis of symmetry; two ferritic steel plates 1 and austenitic steel plates There is an unconstrained connection between the 2.

The geometric shape of the austenitic steel plate forming the energy dissipation structure of the core is shown in Figure 5. The total length of the steel plate with austenitic structure L=2000mm; the length L ₀ =1530mm and the width W ₀ =160mm of the central part of the steel plate (ie the core energy-dissipating section); the thickness T of the steel plate=16mm.

The chemical composition and mass percentage of the steel plate with austenitic structure are: 29.4% Mn, 4.3% Si, 1.4% Al, 0.049% C, 0.009% P, 0.008% S, 0.005% N, the rest is Fe and unavoidable impurity elements. The yield strength of the austenitic steel plate is 304 MPa, and the elongation at break is 52%. The microstructure of the austenitic structure steel plate is a single austenite structure; when entering the yield stage, the metastable austenite undergoes ε martensitic transformation under the action of strain, and under the action of tension-compression alternating load A reversible phase transformation between metastable austenite and strain-induced ε martensite occurs below. The average austenite grain size of the austenitic structure steel plate is 76 μm.

The geometric shape of the ferrite structure steel plate forming the energy dissipation structure of the core is shown in Figure 6. The total length of the steel plate with ferrite structure l=2000mm; the length l 0 of the central part of the steel plate (ie the core energy-dissipating section) l ₀ =1530mm, the width w ₀ /2=80mm; the thickness of the steel plate t=16mm.

The chemical composition and mass percentage of the steel plate with ferrite structure are: 0.30% Mn, 0.05% Si, 0.015% C, 0.05% Ti, 0.012% P, 0.006% S, 0.006% N, the rest is Fe and unavoidable impurity elements. The yield strength of the steel plate with ferrite structure is 157 MPa, and the elongation at break is 47%. The microstructure of the steel plate with ferrite structure is mainly ferrite structure. The average ferrite grain size of the ferrite structure steel plate is 50 μm.

The core energy-dissipating section of the austenitic steel plate has the same length as the core energy-consuming section of the ferritic steel plate. The thickness of the steel plate with the austenitic structure is the same as the thickness of the steel plate with the ferrite structure. The ratio of the sum of the cross-sectional areas of the core energy-dissipating sections of two ferritic steel plates to the cross-sectional area of the core energy-dissipating section of one austenitic steel plate is 1.0 (greater than 0.4).

The front view, top view and side view of the core energy dissipation structure are shown in Fig. 7, Fig. 8 and Fig. 9 respectively.

The peripheral constraining member is a constraining sleeve formed by combining the peripheral constraining steel pipe 4 and the inner filling concrete 3, and the peripheral constraining member plays a role in constraining the lateral displacement of the core energy-dissipating structure and preventing the core energy-dissipating structure from buckling . There is a layer of non-adhesive material between the peripheral constraining member and the core energy-dissipating structure to eliminate friction between the peripheral constraining member and the core energy-dissipating structure.

After assembly, the front view, top view and cross-sectional view along plane A-A of the partially fusible two-stage energy-dissipating axial steel damper are shown in Fig. 10, Fig. 11 and Fig. 12 respectively.

The partially fusible double-stage energy-dissipating axial steel damper is subjected to periodic alternating tensile-compressive plastic deformation with displacements of 3mm, 5mm, 7mm, 9mm, 11mm, 17mm, 20mm, 23mm, 25mm, 28mm, and 31mm, respectively. After 3 cycles of deformation under one displacement condition and no bearing capacity attenuation, the core energy dissipation structure of the axial steel damper did not partially fuse. Fig. 13 is the hysteresis curves of the axial steel damper when the displacements are 3mm, 9mm, 17mm, 25mm and 31mm, corresponding to the periodic alternating tension-compression plastic deformation. Increase the cyclic tension-compression plastic deformation displacement to 34mm, and a ferrite structure steel plate constituting the energy dissipation structure of the core will fail in the second cycle of cyclic deformation; here, under the displacement condition of 34mm, the shaft The steel damper has experienced 3 cycles of deformation in total. Continue to increase the cyclic tension-compression plastic deformation displacement to 37mm, and the second ferrite steel plate that forms the energy dissipation structure of the core also fails in the second week of cyclic deformation; here, under the displacement condition of 37mm , the axial steel damper experienced a total of 3 cycles of deformation. It can be seen that the core energy-dissipating structure of the steel damper is partially fused at displacements of 34 mm and 37 mm; correspondingly, the bearing capacity of the axial steel damper is reduced. Fig. 14 is the hysteresis curve of the partially fusible double-stage energy-dissipating axial steel damper during periodic alternating tension-compression plastic deformation when partial fusing occurs. The maximum allowable displacement of the energy-dissipating structure at the core of the steel damper before partial fusing occurs should be between 31mm and 34mm. The yield displacement of the axial steel damper obtained from the hysteretic curve of the 34mm displacement cyclic deformation is about 3.0mm (actually, the yield displacement of the axial steel damper obtained from the hysteretic curve of the 31mm displacement cyclic deformation is also very close to 3.0mm).

After the energy dissipating structure of the core is partially fused, due to the excellent low-cycle fatigue performance of the austenitic steel plate, the axial steel dampers continue to be 38mm, 41mm, 44mm, 47mm, 50mm, 53mm, 56mm, 59mm, The displacements of 63mm and 67mm were subjected to periodic alternating tension-compression plastic deformation. Under each displacement condition, three cycles of deformation were experienced without bearing capacity attenuation. At this time, the axial steel damper did not fail due to fatigue failure. The above-mentioned plastic deformation displacements all exceed 1/60 of the length of the axial steel damper (about 33.3 mm), that is, the axial steel damper can be displaced by 1/60 of the length of the steel damper after partial fusing Conditions complete at least 30 cycles of periodic alternating tension-compression plastic deformation. Fig. 15 is the hysteresis curves of the axial steel damper when the displacements are 41 mm, 50 mm, 56 mm, 63 mm and 67 mm, corresponding to the periodic alternating tension-compression plastic deformation. The limit allowable displacement of the axial steel damper is greater than 67mm (equivalent to 1/30 of the length of the axial steel damper). The calculated ratio of the limit allowable displacement to the yield displacement of the axial steel damper is greater than 22 (significantly greater than 18).

Therefore, the ratio of the limit allowable displacement to the yield displacement of the partially fusible double-stage energy-dissipating axial steel damper described in this embodiment is not less than 18, and the limit allowable displacement is not less than the partially fusible two-stage energy-dissipating axial steel damper. 1/50 of the length of the damper; and, under this limit allowable displacement condition, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 3 cycles of periodic alternating tension-compression plastic deformation and bearing capacity The attenuation is less than 15%; and, when the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper is partially fused, within the length of the partially fusible two-stage energy-dissipating axial steel damper Under the displacement condition of 1/60, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%. The partially fusible double-stage energy-dissipating axial steel damper can play the role of energy dissipation and shock absorption under earthquakes of different intensities, can fail at the same redundancy as the main structure of the building, and can limit the ultimate output of the steel damper to ensure that the building The reliability of the connection nodes of the object body structure.

Fig. 3 and Fig. 4 are schematic diagrams of the axial energy-dissipating support formed by the combination of the axial steel damper and other steel supports in this embodiment. One end of the axial steel damper 5 is connected to the building gusset plate through the intermediate connecting plate 6 and the ball joint 8, and the other end of the axial steel damper 5 is formed by connecting and combining the intermediate connecting plate 6 and other steel supports 7 Axial energy dissipation support.

Example 2:

The core energy-dissipating structure is composed of an austenitic steel plate and a ferritic steel plate, the austenitic steel plate and the ferritic steel plate have the same longitudinal length; the ferrite steel plate is perpendicular to the austenitic The ferritic structure steel plate is placed; the unconstrained connection between the ferritic structure steel plate and the austenitic structure steel plate.

The geometric shape of the austenitic steel plate forming the energy dissipation structure of the core is shown in Figure 5. The total length of the steel plate with austenitic structure L=2000mm; the length L ₀ =1530mm and the width W ₀ =80mm of the central part of the steel plate (ie the core energy-dissipating section); the thickness T of the steel plate=14mm.

The chemical composition and mass percentage of the austenitic steel plate are: 27.5% Mn, 4.0% Si, 0.6% Al, 0.002% C, 2.0% Ni, 0.7% Cu, 0.007% P, 0.006% S, 0.005% N, the rest is Fe and unavoidable impurity elements. The yield strength of the austenitic steel plate is 229MPa, and the elongation at break is 58%. The microstructure of the austenitic structure steel plate is a single austenite structure; when entering the yield stage, the metastable austenite undergoes ε martensitic transformation under the action of strain, and under the action of tension-compression alternating load A reversible phase transformation between metastable austenite and strain-induced ε martensite occurs below. The average austenite grain size of the austenitic structure steel plate is 126 μm.

The geometric shape of the ferrite structure steel plate forming the energy dissipation structure of the core is shown in Figure 6. The total length of the steel plate with ferrite structure l=2000mm; the length l ₀ =1000mm and the width w ₀ /2=100mm of the central part of the steel plate (ie the core energy-dissipating section); the thickness of the steel plate t=16mm.

The chemical composition and mass percentage of the steel plate with ferrite structure are: 0.18% Mn, 0.05% Si, 0.01% C, 0.04% Ti, 0.01% P, 0.006% S, 0.006% N, the rest is Fe and unavoidable impurity elements. The yield strength of the steel plate with ferrite structure is 122MPa, and the elongation at break is 50%. The microstructure of the steel plate with ferrite structure is mainly ferrite structure. The average ferrite grain size of the ferrite structure steel plate is 86 μm.

The core energy-dissipating section of the austenite structure steel plate is longer than the core energy-dissipating section of the ferrite structure steel plate. The ratio of the cross-sectional area of the core energy-dissipating section of the ferritic steel plate to the cross-sectional area of the core energy-consuming section of the austenitic steel plate is 1.43 (greater than 0.4).

The peripheral constraining member is a constraining sleeve formed by a combination of steel pipes and inner concrete. There is a layer of non-adhesive material between the peripheral constraining member and the core energy-dissipating structure to eliminate friction between the peripheral constraining member and the core energy-dissipating structure.

The partially fusible double-stage energy-dissipating axial steel damper is subjected to 3 cycles of periodic alternating tension-compression plastic deformation with displacements of 5 mm, 10 mm, 25 mm and 35 mm respectively, and the plastic deformation displacement of the tension-compression cycle is increased to 38mm, the steel plate with ferrite structure constituting the core energy-dissipating structure failed in the third cycle of cyclic deformation, that is, the core energy-dissipating structure of the steel damper was partially fused; correspondingly, the axial steel damper The load-carrying capacity of the damper is reduced. The yield displacement of the axial steel damper is about 3.1mm obtained from the hysteretic curve of 38mm displacement cyclic deformation. The yield displacement of the steel damper obtained from the hysteretic curve of the 35mm displacement cyclic deformation is also approximately 3.1mm.

After the core energy-dissipating structure was partially fused, the axial steel damper continued to undergo 30 cycles of periodic alternating tension-compression plastic deformation with a displacement of 48mm. Bearing capacity attenuation. The above-mentioned plastic deformation displacements all exceed 1/60 (about 33.3mm) of the length of the axial steel damper. The axial steel damper undergoes periodic alternate tension-compression plastic deformation with a displacement of 70 mm, and the steel damper fails in the fourth week. Therefore, the limit allowable displacement of the axial steel damper is about 70mm (the displacement of 70mm is equivalent to 1/29 of the length of the axial steel damper), and the limit allowable displacement and yield displacement of the axial steel damper are calculated The ratio is about 22 (significantly greater than 18).

Therefore, the ratio of the limit allowable displacement to the yield displacement of the partially fusible double-stage energy-dissipating axial steel damper described in this embodiment is not less than 18, and the limit allowable displacement is not less than the partially fusible two-stage energy-dissipating axial steel damper. 1/50 of the length of the damper; and, when the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper is partially fused, the partially fusible two-stage energy-dissipating axial steel damper Under the displacement condition of 1/60 of the length of the damper, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%.

Example 3:

The cross-section of the core energy-dissipating structure has a cross-shaped axisymmetric geometry, and its symmetry axis is the axial direction of the steel damper. The cross-section is narrow in the middle and wide at both ends along the axial direction. The core energy-dissipating structure is composed of one austenitic steel plate and two ferritic steel plates, the austenitic steel plate and the ferritic steel plate have the same longitudinal length; the two ferritic steel plates are respectively placed Above and below the steel plate with austenitic structure, the longitudinal centerline of the steel plate with austenitic structure is the axis of symmetry; two steel plates with ferritic structure and the steel plate with austenitic structure are unconstrainedly connected.

The geometric shape of the austenitic steel plate forming the energy dissipation structure of the core is shown in Figure 5. The total length of the steel plate with austenitic structure L=2000mm; the length L ₀ =1530mm and the width W ₀ =160mm of the central part of the steel plate (ie the core energy-dissipating section); the thickness T of the steel plate=12mm.

The chemical composition and mass percentage of the steel plate with austenitic structure are: 23.4% Mn, 5.4% Si, 2.3% Al, 0.04% C, 0.01% P, 0.008% S, 0.005% N, the rest is Fe and unavoidable impurity elements. The yield strength of the austenitic steel plate is 284MPa, and the elongation at break is 44%. The microstructure of the austenitic structure steel plate is a single austenite structure; when entering the yield stage, the metastable austenite undergoes ε martensitic transformation under the action of strain, and under the action of tension-compression alternating load A reversible phase transformation between metastable austenite and strain-induced ε martensite occurs below. The average austenite grain size of the austenitic structure steel plate is 216 μm.

The geometric shape of the ferrite structure steel plate forming the energy dissipation structure of the core is shown in Figure 6. The total length of the steel plate with ferrite structure is l=2000mm; the length l 0 of the central part of the steel plate (ie the core energy-dissipating section) is l ₀ =1530mm, and the width w ₀ /2=80mm; the thickness of the steel plate is t=12mm.

The chemical composition and mass percentages of the ferritic steel plate are: 0.50% Mn, 0.3% Si, 0.095% C, 0.1% Ti, 0.06% Nb, 0.01% P, 0.006% S, 0.005% N, and the rest are Fe and unavoidable impurity elements. The yield strength of the steel plate with ferrite structure is 175 MPa, and the elongation at break is 31.5%. The microstructure of the steel plate with ferrite structure is mainly ferrite structure. The average ferrite grain size of the ferrite structure steel plate is 192 μm.

The partially fusible double-stage energy-dissipating axial steel damper undergoes periodic alternating tension-compression plastic deformation with displacements of 3mm, 9mm, 15mm, 18mm and 22mm respectively, and experiences 3 cycles of deformation under each displacement condition without The bearing capacity is attenuated, and the core energy dissipation structure of the axial steel damper is not partially fused. Increase the tensile-compression cyclic plastic deformation displacement to 26mm, and the first and second ferrite steel plates that make up the energy dissipation structure of the core will fail in the third and fourth cycles of cyclic deformation, respectively. That is, the core energy dissipation structure of the steel damper is partially fused at a displacement of 26 mm. From the hysteresis curve of 26mm displacement cyclic deformation, the yield displacement of the axial steel damper is about 3.0mm.

After the core energy-dissipating structure was partially fused, the axial steel damper continued to undergo 30 cycles of periodic alternating tension-compression plastic deformation with a displacement of 38 mm, and the axial steel damper still did not fail due to fatigue failure and had no Bearing capacity attenuation. The above-mentioned plastic deformation displacements all exceed 1/60 (about 33.3mm) of the length of the axial steel damper. The axial steel damper undergoes periodic alternating tension-compression plastic deformation with a displacement of 58 mm, and the steel damper fails in the sixth cycle. Therefore, the limit allowable displacement of the axial steel damper is greater than 58mm (equivalent to 1/35 of the length of the axial steel damper), and the ratio of the limit allowable displacement of the axial steel damper to the yield displacement is calculated to be approximately Greater than 19.

Therefore, the ratio of the limit allowable displacement to the yield displacement of the partially fusible double-stage energy-dissipating axial steel damper described in this embodiment is not less than 18, and the limit allowable displacement is not less than the partially fusible two-stage energy-dissipating axial steel damper. 1/50 of the length of the damper; and, under the limit allowable displacement condition, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 3 cycles of periodic alternating tension-compression plastic deformation and load The force attenuation is less than 15%; and, when the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper is partially fused, the length of the partially fusible two-stage energy-dissipating axial steel damper Under the displacement condition of 1/60 of , the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%.

Embodiment 4～6:

The main chemical composition (the steel inevitably contains traces of P, S, N and other impurity elements) and mechanical properties of the steel plate with austenitic structure are shown in Table 1. The microstructure of the austenitic structure steel plate is a single austenite structure; when entering the yield stage, the metastable austenite undergoes ε martensitic transformation under the action of strain, and under the action of tension-compression alternating load A reversible phase transformation between metastable austenite and strain-induced ε martensite occurs below. The average austenite grain size of the steel plate with austenitic structure is shown in Table 1.

The main chemical composition (the steel inevitably contains traces of P, S, N and other impurity elements) and mechanical properties of the steel plate with ferrite structure are shown in Table 1. The microstructure of the steel plate with ferrite structure is mainly ferrite structure. The average ferrite grain size of the steel plate with ferrite structure is shown in Table 1.

Table 1

The partially fusible double-stage energy-dissipating axial steel damper undergoes partial fusing in the process of periodic alternating tension-compression plastic deformation. Before partial fusing of the axial steel damper, the axial bearing capacity of the steel damper did not attenuate during the cyclic deformation process. In the process of partial fusing of the axial steel damper, the bearing capacity of the damper is reduced. After partial fusing of the axial steel damper, the steel damper continued 30 cycles of cyclic tension-compression plastic deformation with a displacement of 35 mm without fatigue damage, and the bearing capacity of the steel damper did not attenuate; then, the cyclic plastic deformation continued Deformation obtains the limit allowable displacement of the steel damper. The yield displacement, limit allowable displacement, and ratio of limit allowable displacement to yield displacement of the axial steel damper are shown in Table 2.

Table 2

the	屈服位移(μm)Yield displacement (μm)	极限允许位移(μm)Limit allowable displacement (μm)	极限允许位移与屈服位移之比Ratio of limit allowable displacement to yield displacement
实施例4Example 4	3.33.3	＞68.0>68.0	＞20.6>20.6
实施例5Example 5	3.03.0	＞55.0>55.0	＞18.3>18.3
实施例6Example 6	3.13.1	＞57.0>57.0	＞18.4>18.4

It can be seen from Table 2 that the ratio of the limit allowable displacement to the yield displacement of the partial fusible double-stage energy-dissipating axial steel damper described in Examples 4 to 6 is not less than 18, and the limit allowable displacement is not less than the partial fusible double-stage energy-dissipating axial steel damper. 1/50 of the length of the energy-dissipating axial steel damper; and, under the limit allowable displacement condition, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 3 cycles of periodic alternating tension-compression plasticity Deformation and bearing capacity attenuation is less than 15%; and, when the core energy-dissipating structure of the partially fusible two-stage energy-dissipating axial steel damper is partially fused, the partially fusible two-stage energy-dissipating axial steel damper Under the displacement condition of 1/60 of the length of the damper, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%.

Embodiment 7:

The geometric shape of the austenitic steel plate forming the energy dissipation structure of the core is shown in Figure 5. The total length of the steel plate with austenitic structure L=2000mm; the length L ₀ =1530mm and the width W ₀ =100mm of the central part of the steel plate (ie the core energy-dissipating section); the thickness T of the steel plate=14mm.

The chemical composition and mass percentage of the austenitic steel plate are: 27.5% Mn, 4.0% Si, 0.6% Al, 0.002% C, 2.0% Ni, 0.7% Cu, 0.007% P, 0.006% S, 0.005% N, the rest is Fe and unavoidable impurity elements. The yield strength of the austenitic steel plate is 229 MPa, and the elongation at break is 58%. The microstructure of the austenitic structure steel plate is a single austenite structure; when entering the yield stage, the metastable austenite undergoes ε martensitic transformation under the action of strain, and under the action of tension-compression alternating load A reversible phase transformation between metastable austenite and strain-induced ε martensite occurs below. The average austenite grain size of the austenitic structure steel plate is 126 μm.

The geometric shape of the ferrite structure steel plate forming the energy dissipation structure of the core is shown in Figure 6. The total length of the steel plate with ferrite structure l=2000mm; the length l 0 of the central part of the steel plate (ie the core energy-dissipating section) l ₀ =1530mm, the width w ₀ /2=42mm; the thickness of the steel plate t=16mm.

The length of the core energy-dissipating section of the austenitic steel plate is equal to the length of the core energy-consuming section of the ferritic steel plate. The ratio of the cross-sectional area of the core energy-dissipating section of the ferritic steel plate to the cross-sectional area of the core energy-consuming section of the austenitic steel plate is 0.48 (greater than 0.4).

The partially fusible double-stage energy-dissipating axial steel damper undergoes 3 cycles of periodic alternating tension-compression plastic deformation with a displacement of 30mm, and then undergoes alternate tension-compression plastic deformation with a displacement of 38mm to form a core energy dissipation The steel plate with ferrite structure of the structure suffered fatigue fracture failure in the 4th cycle of 38mm displacement cyclic deformation, that is, the core energy dissipation structure of the steel damper was partially fused. The yield displacement of the axial steel damper is about 4.1mm obtained from the hysteretic curve of 38mm displacement cyclic deformation.

After the core energy-dissipating structure was partially fused, the axial steel damper continued to undergo 30 cycles of periodic alternating tension-compression plastic deformation with a displacement of 38 mm, and the axial steel damper still did not fail due to fatigue failure and had no Bearing capacity attenuation. The above-mentioned plastic deformation displacements all exceed 1/60 (about 33.3mm) of the length of the axial steel damper. The axial steel damper was then subjected to 3 cycles of periodic alternating tension-compression plastic deformation with a displacement of 75mm, and failure just happened. Therefore, the limit allowable displacement of the axial steel damper is 75mm (the displacement of 75mm is equivalent to 1/27 of the length of the axial steel damper), and the difference between the limit allowable displacement and the yield displacement of the axial steel damper is calculated. The ratio is 18.2.

Therefore, the ratio of the limit allowable displacement to the initial yield displacement of the partial fusible double-stage energy dissipation axial steel damper described in this embodiment is not less than 18, and the limit allowable displacement is not less than the partial fusible two-stage energy dissipation shaft 1/50 of the length of the steel damper; and, when the core energy dissipation structure of the partially fusible two-stage energy dissipation axial steel damper is partially fused, the partially fusible two-stage energy dissipation axial Under the displacement condition of 1/60 of the length of the steel damper, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%.

Comparative example 1:

The chemical composition and mass percentage of the austenitic steel plate are: 27.5% Mn, 4.0% Si, 0.6% Al, 0.002% C, 2.0% Ni, 0.7% Cu, 0.007% P, 0.006% S, 0.005% N, the rest is Fe and unavoidable impurity elements. The yield strength of the austenitic steel plate is 229MPa, and the elongation at break is 58%. The average austenite grain size of the austenitic structure steel plate is 126 μm.

The geometric shape of the ferrite structure steel plate forming the energy dissipation structure of the core is shown in Figure 6. The total length of the steel plate with ferrite structure l=2000mm; the length l 0 of the central part of the steel plate (ie the core energy-dissipating section) l ₀ =1530mm, the width w ₀ /2=34mm; the thickness of the steel plate t=16mm.

The length of the core energy-dissipating section of the austenitic steel plate is equal to the length of the core energy-consuming section of the ferritic steel plate. The ratio of the cross-sectional area of the core energy-dissipating section of the ferritic steel plate to the cross-sectional area of the core energy-consuming section of the austenitic steel plate is 0.389 (less than 0.4).

The partially fusible double-stage energy-dissipating axial steel damper undergoes 3 cycles of periodic alternating tension-compression plastic deformation with a displacement of 30mm, and then undergoes alternate tension-compression plastic deformation with a displacement of 38mm to form a core energy dissipation The steel plate with ferrite structure of the structure suffered fatigue fracture failure in the sixth cycle of 38mm displacement cyclic deformation, that is, the core energy dissipation structure of the steel damper was partially fused. The yield displacement of the axial steel damper is about 4.5mm obtained from the hysteretic curve of 38mm displacement cyclic deformation.

After the core energy-dissipating structure was partially fused, the axial steel damper continued to undergo 30 cycles of periodic alternating tension-compression plastic deformation with a displacement of 38 mm, and the axial steel damper still did not fail due to fatigue failure and had no Bearing capacity attenuation. The axial steel damper undergoes periodic alternating tension-compression plastic deformation with a displacement of 75 mm, and failure occurs at 3.5 cycles. Therefore, the limit allowable displacement of the axial steel damper is about 75mm. Calculate the ratio of the limit allowable displacement to the yield displacement of the axial steel damper to be about 16.7. Therefore, the ratio of the limit allowable displacement to the yield displacement of the partially fusible double-stage energy-dissipating axial steel damper described in this comparative example is less than 18.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

A core energy-dissipating structure with partially fusible two-stage energy dissipation is used for axial steel dampers to absorb external shock energy when the axial steel dampers are subjected to periodic alternating tension-compression plastic deformation, It is characterized in that,

The partially fusible double-stage energy dissipation core energy dissipation structure includes at least one austenitic structure steel plate and one ferrite structure steel plate, and there is no gap between the ferrite structure steel plate and the austenite structure steel plate Constrained connections,

The microstructure of the austenitic steel plate is composed of metastable austenite and thermally induced ε martensite with a volume fraction not exceeding 15%, and the average grain size of the metastable austenite is not more than 400 μm, During tensile or compressive plastic deformation, the metastable austenite of the austenitic steel plate induces the ε martensitic transformation under the action of strain and the α′ martensitic transformation is suppressed; During stretch-compression plastic deformation, a reversible phase transformation between austenite and strain-induced ε martensite occurs inside the steel plate with austenitic structure;

The microstructure of the ferritic steel plate is mainly ferrite, and the average grain size of ferrite is not more than 200 μm;

The yield strength of the austenitic steel plate is not less than 220MPa, and the elongation at break is not less than 40%, and the yield strength of the steel plate with ferrite structure is less than 180MPa, and the elongation at break is not less than 30%;

The ratio of the sum of the cross-sectional areas of the core energy-dissipating sections of all ferritic steel plates to the sum of the cross-sectional areas of the core energy-dissipating sections of all austenitic steel plates is not less than 0.4.
According to claim 1, a partially fusible double-stage energy-dissipating core energy-dissipating structure is characterized in that, if the cross-sectional geometry of the ferrite structure steel plate or austenite structure steel plate is maintained along the length direction unchanged, then the core energy-consuming section of the ferritic steel plate or austenitic steel plate is the full length of the ferritic steel plate or austenitic steel plate; if the ferritic steel plate or The cross-sectional geometric shape of the austenitic steel plate presents the characteristics of wide ends and narrow middle along the length direction, then the core energy-consuming section of the ferritic steel plate or the austenitic steel plate is the ferrite steel plate or The narrow part in the middle of the austenitic steel plate.
The energy-dissipating core structure of a partially fusible two-stage energy-dissipating core according to claim 1, wherein the mass percentage of the chemical composition of the austenitic structure steel plate is: C≤0.15%, 20.0%≤ Mn≤34.0%, 3.5%≤Si≤6.0%, Al≤2.5%, Ni≤5.0%, Cu≤2.0%, P≤0.03%, S≤0.03%, N≤0.02%, the rest is Fe and unavoidable The impurity elements, wherein, the mass percentages of Al, Ni and Cu also satisfy the following relationship: Ni/Cu≥0.25 and Al+0.4Ni+0.25Cu≤3.5%.
A partially fusible double-stage energy-dissipating core energy-dissipating structure according to claim 1, wherein the mass percentage of the chemical composition of the ferrite structure steel plate is: C≤0.1%, Mn≤1.0 %, Si≤0.8%, Ti≤0.15%, Nb≤0.1%, V≤0.2%, P≤0.03%, S≤0.03%, N≤0.02%, and the rest are Fe and unavoidable impurity elements.
A core energy dissipation structure with partially fusible two-stage energy dissipation according to claim 1, characterized in that the cross section of the core energy dissipation structure is selected as an axisymmetric geometry.
A partially fusible double-stage energy dissipation core energy-dissipating structure according to claim 1, characterized in that the length l0 of the core energy-dissipating section of the ferrite structure steel plate constituting the core energy-dissipating structure is not greater than The length L 0 of the core energy-dissipating section of the austenitic steel plate.
A partially fusible double-stage energy-dissipating axial steel damper, characterized in that it comprises a partially fusible dual-stage energy-dissipating core energy-dissipating structure and peripheral restraint members according to any one of claims 1-6, The peripheral constraining members mentioned above play the role of constraining the lateral displacement of the core energy-dissipating structure and preventing buckling and instability of the core energy-dissipating structure.
A partially fusible double-stage energy-dissipating axial steel damper according to claim 7, wherein the peripheral constraining member is selected as a constraining sleeve formed by a combination of steel pipes and filled concrete, or a reinforced concrete constraining Casing, or pure steel structural constraints.
A partially fusible double-stage energy-dissipating axial steel damper according to claim 7, wherein the ratio of the limit allowable displacement to the yield displacement of the partially fusible double-stage energy-dissipating axial steel damper is not greater than Less than 18, and the limit allowable displacement is not less than 1/50 of the length of the partially fusible double-stage energy-dissipating axial steel damper;

And, under the limit allowable displacement condition, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 3 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%;

Moreover, when the core energy-dissipating structure of the partially fusible double-stage energy-dissipating axial steel damper is partially fused, the partial fusible double-stage energy-dissipating axial steel damper has a displacement of 1/60 of the length of the axial steel damper Under certain conditions, the partially fusible double-stage energy-dissipating axial steel damper can complete at least 30 cycles of periodic alternating tension-compression plastic deformation and the bearing capacity attenuation is less than 15%.
A partially fusible double-stage energy-dissipating axial steel damper according to claim 7, wherein the partially fusible double-stage energy-dissipating axial steel damper is used alone or combined with other steel supports to form a shaft The energy-dissipating support is installed in a building or structure, and is connected with the beam-column main structure of the building or structure to form a whole, which plays the role of dissipating external vibration energy.