A high-rise building structure vibration control optimization method

Abstract

The application discloses a high-rise building structure vibration control optimization method, which comprises the following steps: firstly, vibration response analysis, by improving the structural resistance, strengthening the structural shape design, and applying the damper auxiliary seismic isolation device, the maximum structural response is ensured to be greater than or equal to the structural response design value, and vibration response control is realized; secondly, resonance analysis, the structural inherent frequency is optimized by considering the structural member redundancy and constraint condition, so that the structural inherent frequency omega is far away from the external excitation load frequency theta, and resonance control of the structure and the external action load is realized; then, the whip effect analysis, the vibration frequency of the top auxiliary facility is optimized by considering the structural member redundancy and constraint condition, so that the whip effect of the top auxiliary facility does not induce the secondary resonance of the structure, and the secondary resonance control of the structure and the top auxiliary facility is realized; the application considers the resonance problem of the high-rise building and the whip effect problem of the top auxiliary device, and is a supplement and improvement of the general method of the existing vibration response control of the high-rise building.

Description

Technical Field

[0001] This invention relates to the field of vibration control of high-rise building structures, and specifically to an optimization method for vibration control of high-rise building structures. Background Technology

[0002] Currently, my country's urbanization process is accelerating, leading to an increasing demand for high-rise and even super high-rise buildings. However, significant structural vibrations in high-rise buildings still occur frequently, often accompanied by public panic and negative social impacts. This also increases public concern about the large-scale construction of high-rise buildings, such as the SEG Plaza in Shenzhen on May 18, 2021. Figure 1 , Figure 2 The building (355.8 meters tall, 79 floors in total, 75 above ground and 4 below) experienced a vibration incident. Shoppers on the 35th, 55th and 60th floors felt the shaking, and floor fans in the rooms swayed noticeably. Although no personal injury or property damage was caused, the related video quickly spread on the Internet and became a trending topic. The subsequent investigation found that the cumulative damage to the top floor slab and mast connection points changed the structural frequency and damping ratio characteristics, causing the mast (antenna) and the building to resonate.

[0003] Vibration problems in high-rise building structures have been a long-standing issue. Theoretical research mainly includes three parts: vibration response, resonance, and whiplash effect. However, in practical engineering, people usually take measures such as improving the structural shape, increasing the structural resistance, and applying dampers and seismic isolation devices to control the structural vibration response (reduce the maximum amplitude of the structure) to meet design requirements. For the deeper resonance problem, especially the potential whiplash effect of rooftop facilities (water towers, masts, communication equipment) in high-rise buildings, there are still no mature solutions available, and the level of decision-making in this area needs further improvement.

[0004] Therefore, based on existing general methods for vibration control of high-rise building structures dedicated to vibration response control, this invention further proposes an optimized method for vibration control of high-rise building structures, taking into account deeper resonance problems and whiplash effects of top-mounted auxiliary devices. This is essential for implementing more targeted design, maintenance, and management. Summary of the Invention

[0005] The purpose of this invention is to further implement scientific design, maintenance and management decisions for high-rise building structures, and to solve the problems of existing general methods for vibration control of building structures that only consider vibration response control and ignore resonance and secondary resonance control. This invention proposes an optimized method for vibration control of high-rise building structures. That is, based on existing general methods for vibration control of high-rise building structures that focus on vibration response control, it is also necessary to keep the natural frequency of the structure away from the frequency of common external excitation loads and the vibration frequency of the top auxiliary facilities, so as to avoid resonance or secondary resonance induced by the whiplash effect of the top auxiliary facilities.

[0006] General methods for vibration control of high-rise buildings that are currently used in practical engineering projects to control structural vibration response.

[0007] (1) Improve structural resistance. Let R max The vibration response of a structure under external excitation loads (earthquake loads, wind loads) can be represented by the structural stress response and structural displacement response, i.e., R. max This represents the maximum response value of a structure under external excitation loads (seismic loads, wind loads). When the structure is in the preliminary design phase, if R... max ≥R design At this point, the structure is unsafe. Measures need to be taken, such as increasing the cross-sectional area of ​​the structural members and increasing the reinforcement, to increase the structural resistance and ultimately improve R. max ≤R design To ensure structural safety.

[0008] (2) Strengthen structural shape design. Considering wind load, let λ represent the drag coefficient of the structural section. When numerical simulation or wind tunnel test results show that the structure has R at this time... max ≥R design Then it is necessary to further improve the shape of the structural members, and a flatter section can be adopted. If necessary, air ducts should be added to reduce the impact of wind load and make R max ≤R design To ensure structural safety.

[0009] (3) Apply damper-assisted seismic isolation devices. Typically, the maximum displacement of a high-rise building under external excitation load occurs at the top floor. At this point, let R... 0 max R represents the maximum displacement of the top floor of the structure. 0 design This represents the maximum amplitude of vibration that a group of people can psychologically withstand, i.e., when the structural vibration amplitude R... 0 max Greater than R 0 design At that time, people will feel uncomfortable, and may even panic, even at this time The structure is in a safe condition. In such cases, large vibration damping devices are typically installed on the roof of the building to reduce the amplitude of structural vibrations. Ensure the structure provides a comfortable user experience.

[0010] The technical solution adopted to achieve the above objectives is:

[0011] A method for optimizing vibration control in high-rise building structures, characterized by comprising the following steps:

[0012] a. First, perform a vibration response analysis. Let R represent the vibration response of the structure under seismic or wind loads. Parameters such as structural displacement, stress, strain, and acceleration can be used. max R represents the maximum response value of the structure under external excitation load. design This represents the structural response design value, which is achieved by increasing structural resistance, strengthening structural shape design, and applying dampers and associated seismic isolation devices to ensure R. max ≤R design To achieve vibration response control of high-rise building structures;

[0013] b. Next, resonance analysis is performed. Let θ represent the frequency of the external harmonic load, and ω represent the natural frequencies of the structure. When the natural frequencies of the structure are close to the frequency of the external load, i.e. The structure will resonate; analyze the frequency range of common external excitation loads, consider the redundancy of structural members and constraints to optimize the structure's natural frequency, making the structure's natural frequency far away from the frequency of the external excitation load, i.e. or To avoid resonance between the structure and external loads, and to achieve resonance control between the structure and external loads;

[0014] c. Then, a whiplash effect analysis is performed. Let R1 represent the displacement response of the top-mounted ancillary facilities, including masts, communication devices, and water towers, under seismic or wind loads, and R0 represent the displacement response of the structure under seismic or wind loads. R1 ≥ 10R0, indicating a whiplash effect. The vibration frequency range of these ancillary facilities is analyzed. Considering the redundancy of structural members and constraints, the vibration frequency of the top-mounted ancillary facilities is optimized to be far from the structure's natural frequency, i.e., the absolute value of the difference between the two frequencies is greater than 0. This prevents the whiplash effect of the top-mounted ancillary facilities from inducing secondary resonance in the structure, thus achieving secondary resonance control between the structure and the top-mounted ancillary facilities. For example, let the stiffness of the top-mounted ancillary facilities be k1 and the mass be m1, and the stiffness of the structure be k2 and the mass be m2. When k2 and m2 are multiples of k1 and m1, taking k2 ≥ 90k1 and m2 ≥ 90m1, R1 ≥ 10R0 will occur, indicating a whiplash effect.

[0015] Furthermore, in step c, when analyzing the secondary resonance of the complex auxiliary facilities system at the top, attention should be paid to the accumulation of structural damage caused by years of wind and sun exposure and disrepair, which leads to a change in its vibration frequency, causing it to approach or equal the natural frequency of the structure, thus triggering secondary resonance.

[0016] The beneficial effects of this invention patent are as follows:

[0017] This invention presents an optimized method for vibration control of high-rise building structures. It first considers existing general methods such as enhancing structural resistance, strengthening structural shape design, and applying dampers and associated seismic isolation devices to achieve vibration response control. Ultimately, efficient vibration control is achieved by distancing the structure's natural frequencies from common external excitation load frequencies and the vibration frequencies of rooftop attachments. This invention also considers deeper resonance issues and the whiplash effect of rooftop attachments in high-rise buildings, proposing an optimized vibration control method for high-rise building structures. This method supplements and improves existing general methods for vibration response control in high-rise buildings, contributing to more scientific and targeted design, maintenance, and management. Attached Figure Description

[0018] Figure 1 This is a flowchart of the present invention;

[0019] Figure 2 This is a schematic diagram of a two-story rigid frame structure and the action of a simple harmonic load.

[0020] Figure 3 for Figure 2 A schematic diagram showing the variation of the principal vibration modes of a two-story rigid frame structure with respect to mass and stiffness factor n under a harmonic load. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] A method for optimizing vibration control in high-rise building structures, characterized by comprising the following steps:

[0023] a. First, perform a vibration response analysis. Let R represent the vibration response of the structure under seismic or wind loads. Parameters such as structural displacement, stress, strain, and acceleration can be used. max R represents the maximum response value of the structure under external excitation load. design This represents the structural response design value, which is achieved by increasing structural resistance, strengthening structural shape design, and applying dampers and associated seismic isolation devices to ensure R. max ≤R design To achieve vibration response control of high-rise building structures;

[0024] b. Next, resonance analysis is performed. Let θ represent the frequency of the external harmonic load, and ω represent the natural frequencies of the structure. When the natural frequencies of the structure are close to the frequency of the external load, i.e. The structure will resonate; analyze the frequency range of common external excitation loads, consider the redundancy of structural members and constraints to optimize the structure's natural frequency, making the structure's natural frequency far away from the frequency of the external excitation load, i.e. or To avoid resonance between the structure and external loads, and to achieve resonance control between the structure and external loads;

[0025] c. Then, whiplash effect analysis is performed. Let R1 represent the displacement response of the top-mounted ancillary facilities, including masts, communication devices, and water towers, under seismic or wind loads, and R0 represent the displacement response of the structure under seismic or wind loads. R1 ≥ 10R0, i.e., whiplash effect occurs. Analyze the vibration frequency range of such ancillary facilities, and optimize the vibration frequency of the top-mounted ancillary facilities considering the redundancy of structural members and constraints, so that it is far away from the natural frequency of the structure, i.e., the absolute value of the difference between the two is greater than 0, so as to avoid the whiplash effect of the top-mounted ancillary facilities inducing secondary resonance in the structure, and achieve secondary resonance control between the structure and the top-mounted ancillary facilities.

[0026] Furthermore, in step c, when analyzing the secondary resonance of the complex auxiliary facilities system at the top, attention should be paid to the accumulation of structural damage caused by years of wind and sun exposure and disrepair, which leads to a change in its vibration frequency, causing it to approach or equal the natural frequency of the structure, thus triggering secondary resonance.

[0027] like Figure 1 The diagram shows a flowchart of an optimization method for vibration control of high-rise building structures. It includes theoretical analysis of prominent vibration problems in high-rise building structures, including vibration response under earthquake and wind loads, resonance, and whiplash effect; general methods for vibration control of high-rise building structures in practical engineering, including strengthening the structural design, improving structural resistance, and applying dampers as additional vibration reduction and isolation measures; and an optimization method for vibration control of high-rise building structures considering resonance and whiplash effect. This method first adopts existing general methods for vibration control of high-rise building structures to achieve structural vibration response control. Based on this, it further studies the structure's natural frequency, keeping it away from the frequencies of common external excitation loads. For cases where water towers, masts, or communication devices are installed on the top of the structure, it is also necessary to ensure that the vibration frequency of these devices maintains a certain difference from the structure's natural frequency to avoid secondary resonance caused by the whiplash effect of the top-mounted devices.

[0028] Figure 2This diagram illustrates a two-story rigid frame structure under harmonic load. P represents the peak force of the harmonic load, θ is the frequency of the harmonic load, t is the duration of the harmonic load, m1 and m2 are the masses of the first and second floor slabs, respectively, and k1 and k2 are the stiffnesses of the first and second floor sidewalls, respectively. The sidewalls are fixed to the ground boundary. From structural dynamics, this two-story rigid frame structure can be simplified to a two-degree-of-freedom system. Let ω1 and ω2 represent the two vibration frequencies of this two-degree-of-freedom system, respectively. Resonance and whiplash effect analyses are performed as follows:

[0029] (1) Resonance Analysis. Considering the special case, i.e., m1=m2=m and k1=k2=k, let β1 and β2 represent the dynamic amplification coefficients of the two-degree-of-freedom system, respectively. The mathematical expressions for β1 and β2 are as follows:

[0030]

[0031] Draw a schematic diagram of the mathematical changes of β1 and β2, when and At that time, the two-layer rigid frame structure will resonate.

[0032] (2) Whiplash effect analysis. Let m1 = nm2, k1 = nk2, and Y1 and Y2 represent the displacements of the first and second floors, respectively. From the free vibration frequency equations of these two floors, the expressions for the free vibration frequencies of these two degrees of freedom are as follows:

[0033] The expression for the principal mode shape corresponding to the first-order frequency ω1 is as follows.

[0034]

[0035] The expression for the principal mode shape corresponding to the second-order frequency ω2 is as follows.

[0036]

[0037] Figure 3 The diagram illustrates the changes in the principal vibration modes of the two-story rigid frame structure with respect to the mass and stiffness ratio n. It can be seen that as the mass ratio n increases, the proportion of the principal vibration modes of the two-degree-of-freedom system continuously increases. Considering the extreme case, when n is 100, that is, when the mass m1 of the first floor and the stiffness k1 of the side wall are 100 times that of the mass m2 of the second floor and the stiffness k2 of the side wall, the proportion of the two principal vibration modes of the two-degree-of-freedom system exceeds 10, that is, the displacement of the second floor is about 10 times that of the first floor.

[0038] This embodiment does not impose any limitation on the shape, material, structure, etc. of this invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this invention shall fall within the protection scope of this invention.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention patent, and are not intended to limit it. Although the present invention patent has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention patent.

Claims

1. A high-rise building structure vibration control optimization method characterized by, Comprising the following steps: a. First, the vibration response analysis is carried out, let R represent the vibration response of the structure under the action of earthquake load or wind load, the structure displacement, stress, strain or acceleration parameter can be taken, R max represents the maximum response value of the structure under the action of external excitation load, R design represents the design value of the structure response, by improving the structural resistance, strengthening the structural design, applying the damper and the auxiliary seismic isolation device, to ensure that R max ≤R design , realize the vibration response control of high-rise building structure; b. Secondly, resonance analysis is carried out, let θ represent the frequency of external excitation harmonic load, ω represent the natural frequency of structure vibration, when the natural frequency of structure vibration is close to the frequency of external excitation harmonic load of structure, that is , resonance will occur in the structure; the range of common external excitation load frequency value is analyzed, the natural frequency of structure vibration is optimized considering the redundancy of structure bar and constraint condition, so that the natural frequency of structure vibration is far away from the frequency of external excitation harmonic load, that is <0.75 or Avoiding the resonance of structure and external load, realizing the resonance control of structure and external load. c. Then whip effect analysis is carried out, R1 represents the displacement response of the top accessory of the structure under the action of seismic load or wind load, the top accessory of the structure includes mast, communication device, water tower, and R0 represents the displacement response of the structure under the action of seismic load or wind load, R1≥10R0, that is, whip effect occurs; the vibration frequency value range of the accessory is analyzed, the redundancy and constraint conditions of the structural members are considered, and the vibration frequency of the top accessory is optimized to be far away from the natural frequency of the structure, that is, the absolute value of the difference between the two is greater than 0, so as to prevent the whip effect of the top accessory from inducing secondary resonance of the structure, and to realize secondary resonance control of the structure and the top accessory.

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